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CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – Troubleshooting and Repair Manual

Engine Performance Troubleshooting Tree – ISX CM871

Symptoms

    • Engine Acceleration or Response Poor
    • Cranking Fuel Pressure is Low
    • Engine Operating Fuel Pressure is Low
    • Engine Difficult to Start or Will Not Start (Exhaust Smoke)
    • Engine Difficult to Start or Will Not Start (No Exhaust Smoke)
    • Engine Power Output Low
    • Engine Runs Rough at Idle
    • Engine Runs Rough or Misfires
    • Engine Speed Surges at Low or High Idle
    • Engine Speed Surges Under Load or in Operating Range
    • Smoke, Black – Excessive
    • Smoke, White – Excessive
    • Engine Shuts Off or Dies Unexpectedly or Dies During Deceleration
    • Engine Starts But Will Not Keep Operating
    • Engine Will Not Reach Rated Speed (rpm)
    • Engine Run-on or Will Not Shut Down.

How To Use This Tree

This symptom tree can be used to troubleshoot all performance-based symptoms listed above. Start by performing Step 1 troubleshooting. Step 2 asks a series of questions and will provide a list of troubleshooting steps to perform, depending on the symptom. Perform the list of troubleshooting in the sequence shown in the Specifications/Repair section of the tree.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM. Use the following procedure in the Troubleshooting and Repair Manual, CM871 and CM876 Electronic Control Systems, ISX and ISM Engines, Bulletin 4021560. Refer to Procedure 019-032 in Section 19.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Perform basic troubleshooting procedures.  
  STEP 1A. Check for active fault codes or high counts of inactive fault codes. Active fault codes or high counts of inactive fault codes?
  STEP 1B. Perform basic troubleshooting checks. All steps verified to be correct?
  STEP 1C. Perform INSITE™ electronic service tool monitor test. ‘Engine Operating State’ reading a value that can cause an engine derate?
STEP 2. Determination of engine symptom.  
  STEP 2A. Low power, poor acceleration, or poor response. Engine symptom – Low Power, Poor Acceleration, or Poor Response?
  STEP 2B. Engine misfire. Engins symptom – Engine Misfires
  STEP 2C. Excessive black smoke. Engine symptom – Excessive Black Smoke?
  STEP 2D. Excessive white smoke. Engine symptom – Excessive White Smoke and the Engine is Using Coolant?
  STEP 2D-1. Excessive white smoke.
  STEP 2E. Engine speed surge or engine speed unstable. Engine symptom – Engine Speed Surge or Engine Speed Unstable?
  STEP 2F. Engine will not start or difficult to start. Engine symptom – Engine Difficult to Start or Will Not Start?
  STEP 2G. Engine stalls or shuts off unexpectedly. Engine symptom – Engine Stalls or Shuts Off Unexpectedly?
  STEP 2H. Engine run-on or will not shut down. Engine symptom – Engine Run-On or Slow to Shut Down after operating at high idle for 1 minute then keyed OFF?
STEP 3. No-start troubleshooting procedures.  
  STEP 3A. Verify the fuel system has been primed. Fuel system been properly primed?
  STEP 3B. Check fuel shutoff valve voltage. Fuel shutoff valve voltage greater than 11-VDC?
  STEP 3B-1. Check the keyswitch voltage.
  STEP 3B-2. Check the fuel shutoff valve wire.
  STEP 3B-3. Check the ECM power and ground.
  STEP 3C. Check fuel shutoff valve resistance. Fuel shutoff solenoid resistance: 1 to 5 ohms for 6-VDC solenoids; 6 to 15 ohms for 12-VDC solenoids; 24 to 50 ohms for 24-VDC solenoids; 42 to 80 ohms for 32-VDC solenoids; 46 to 87 ohms for 36-VDC solenoids; 92 to 145 ohms for 48-VDC solenoids; 315 to 375 ohms for 74-VDC solenoids; or 645 to 735 ohms for 115-VAC solenoids?
  STEP 3D. Check the fuel shutoff valve actuator. Debris or damage found on the valve disc, valve seat, or actuator disc?
  STEP 3E. Check for correct priming pump operation, if equipped. Lift pump operates after turning the keyswitch ON?
  STEP 3E-1. Check priming pump pressure.
  STEP 3F. Check for coolant in the EGR transfer tube. Coolant present in the crossover tube?
STEP 4. Fuel system checks.  
  STEP 4A. Verify the fuel system has been primed. Fuel system properly primed?
  STEP 4B. Check for air in the fuel. Air bubbles visible in the coil of clear tubing?
  STEP 4C. Check for fuel inlet restriction. Fuel inlet restriction less than the specifications listed? Dirty – 305 mm-Hg [12 in-Hg]; New – 203 mm-Hg [8 in-Hg]
  STEP 4D. Check for drain line restriction. Fuel drain line restriction less than 229 mm-Hg [9 in-Hg]?
  STEP 4E. Check rail fuel pressure. Rail fuel pressure meets the specification?
  STEP 4E-1. Check the pressure side fuel filter restriction
  STEP 4E-2. Check 1724 kPa [250 psi] pressure regulator.
  STEP 4E-3. Check 2206 kPa [320 psi] or 2620 kPa [380 psi] pressure regulator.
STEP 5. Injector and Actuator Diagnostics.  
  STEP 5A. Perform the injector check valve leak test. Injector leak test detects a leaking injector?
  STEP 5B. Perform INSITE™ electronic service tool Cylinder Performance Test. INSITE™ electronic service tool Cylinder Performance Test identifies a single malfunctioning injector?
  STEP 5B-1. Perform INSITE™ electronic service tool Cylinder Performance Test at 600 rpm.
  STEP 5B-2. Perform INSITE™ electronic service tool Cylinder Performance Test at 700 rpm.
  STEP 5B-3. Perform INSITE™ electronic service tool Cylinder Performance Test at 800 rpm.
  STEP 5C. Perform INSITE™ electronic service tool Cylinder Cutout Test. Cylinders pass the cylinder cutout test?
  STEP 5C-1. Perform INSITE™ electronic service tool Cylinder Cutout Test on both injector banks.
  STEP 5C-2. Perform INSITE™ electronic service tool Cylinder Cutout Test.
  STEP 5C-3. Verify overhead adjustments are correct for the suspected malfunctioning injector.
  STEP 5D. Swap the front and rear metering actuators. Cylinder performance test finds a malfunctioning bank?
  STEP 5E. Swap the front and rear timing actuators. Malfunctioning bank follows the timing actuator?
  STEP 5F. Monitor the engine percent load value with INSITE™ electronic service tool. (Perform this step for troubleshooting low power only.) Engine percent load value consistently above 8 percent?
STEP 6. Air handling diagnostic checks.  
  STEP 6A. Start the engine and read the fault codes. Active fault codes?
  STEP 6B. Check air intake restriction. Air intake restriction greater than 635 mm-H2O [25 in-H2O] for a used air filter or 254 mm-H2O [10 in-H2O] for a new filter?
  STEP 6C. Inspect the charge-air cooler. Pressure drop 34 kPa [5 psi] or less in 15 seconds?
  STEP 6D. Inspect the turbocharger blades for damage. Damage found on turbocharger blades?
  STEP 6E. Inspect the turbocharger shaft movement. Nozzle slides evenly from stop to stop and gear teeth undamaged?
STEP 7. Check EGR valve for proper operation.  
  STEP 7A. Check for EGR-related fault codes. EGR-related fault codes present?
  STEP 7B. Check for inactive EGR differential pressure sensor fault codes. Fault Code 1866, 2273, or 2274 active?
  STEP 7C. Check the EGR differential pressure tubes for leaks. Leaks detected at either the low or high EGR differential pressure tubes?
  STEP 7D. Check the EGR differential pressure sensor adapter for leaks. Leaks detected at the EGR differential pressure sensor adapter?
  STEP 7E. Check the EGR differential pressure tubes for plugging. Debris or soot found in either EGR differential pressure tube?
  STEP 7F. Check for air leaks in the EGR system. Leaks found in the EGR connection tubing?
STEP 8. Verify electronic features are operating correctly.  
  STEP 8A. Verify accelerator pedal travel. Accelerator pedal reads 0 when the accelerator is released and 100 percent when the accelerator is depressed?
  STEP 8B. Monitor vehicle speed. Vehicle speed reads 0 when the vehicle is not moving?
  STEP 8C. Verify electronic feature settings are correct. Electronic features set correctly?
  STEP 8D. Check the ambient air pressure sensor accuracy. Barometric pressure sensor reading in INSITE™ electronic service tool within 5 percent of the present local barometric pressure reading?
  STEP 8E. Check the intake manifold pressure sensor accuracy. INSITE™ electronic service tool reading within 17 kPa [2.5 psi] of mechanical gauge reading?
STEP 9. Perform base engine mechanical checks.  
  STEP 9A. Verify injection timing is correct. Injection timing correct?
  STEP 9B. Verify overhead adjustments are correct. Overhead settings within the reset limits?
  STEP 9C. Verify engine brake adjustment. Engine brake settings within the reset limits?
  STEP 9D. Verify crankshaft tone wheel is not loose. Crankshaft tone wheel loose?
  STEP 9E. Check exhaust restriction. Exhaust restriction greater than 305 mm-Hg [12.0 in-Hg]?
  STEP 9F. Verify engine blowby is within specification. Engine blowby measurements within specification?
STEP 10. Aftertreatment checks.  
  STEP 10A. Check for aftertreatment-related fault codes. Fault codes related to the aftertreatment system found to be active?
  STEP 10B. Perform basic aftertreatment troubleshooting checks. All parts inspected and appear to be functioning properly?
  STEP 10C. Check for signs of internal damage to the aftertreatment system. Any visible smoke (black or white) present during the snap throttle acceleration?
  STEP 10D. Check exhaust restriction. Exhaust restriction greater than 305 mm-Hg [12.0 in-Hg]?

Guided Step 1 – Perform basic troubleshooting procedures.

Guided Step 1A – Check for active fault codes or high counts of inactive fault codes.

Conditions

  • Connect INSITE™ electronic service tool.
  • Turn keyswitch ON.

Action

Check for active fault codes or high counts of inactive fault codes.

  • Use INSITE™ electronic service tool to read the fault codes.

Active fault codes or high counts of inactive fault codes?
YES NO
No Repair No Repair
Go to appropriate fault code troubleshooting tree

Guided Step 1B – Perform basic troubleshooting checks.

Conditions

N/A

Action

The following items must be checked or verified before continuing:

  • Verify the fuel level in the tanks.
  • Verify there have not been any changes to CPL components on the engine.
  • Verify fuel grade is correct for the application.
  • Verify the engine is operating within the recommended altitude.
  • Verify engine oil is at the correct level.
  • Verify engine parasitics have not changed.
  • Verify engine duty cycle has not changed.
  • Verify engine cranking speed is greater than 150 rpm.
  • Verify battery voltage is within specification.

All steps verified to be correct?
YES NO
No Repair

Correct the out-of-specification item and verify complaint is no longer present after repair.

Repair complete

Guided Step 1C – Perform INSITE™ electronic service tool monitor test.

Conditions

  • Connect INSITE™ electronic service tool.
  • Operate engine at the speed and load where the symptom occurs.

Action

Use INSITE™ electronic service tool to monitor the parameter ‘Engine Operating State’ at the same engine operating conditions where the symptom occurs.

Refer to Advanced Engine Performance Troubleshooting Techniques, Bulletin 4021686, for a description of what “User Fueling States (Engine Operating States)” can cause engine derates.

‘Engine Operating State’ reading a value that can cause an engine derate?
YES NO

Determine if the engine derate is being caused by normal engine operation or by actual engine damage.

Continue following troubleshooting steps as outlined in Step 2 if an engine failure is suspected.

 No Repair

Guided Step 2 – Determination of engine symptom.

Guided Step 2A – Low power, poor acceleration, or poor response.

Action

Interview the driver and verify the complaint.

Engine symptom Low Power, Poor Acceleration, or Poor Response?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 4 – Fuel System Checks
  • Step 6 – Air Handling Checks
  • Step 7 – EGR Checks
  • Step 10 – Aftertreatment Checks
  • Step 8 – Electronic Checks
  • Step 5 – Injector Checks
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2B – Engine misfire.

Action

Interview the driver and verify the complaint.

Engins symptom – Engine Misfires
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 5 – Injector Checks
  • Step 4 – Fuel System Checks
  • Step 9 – Base Engine Checks
  • Step 7 – EGR Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2C – Excessive black smoke.

Action

Interview the driver and verify the complaint.

Progressive damage to the aftertreatment system has occurred if black smoke is visible. Remove the exhaust aftertreatment system from the vehicle and inspect for reuse. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Inspect the aftertreatment system for potential damage. Refer to Procedure 011-049 in Section 11.

Engine symptom – Excessive Black Smoke?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 6 – Air Handling Checks
  • Step 7 – EGR Checks
  • Step 4 – Fuel System Checks
  • Step 5 – Injector and Actuator Diagnostics
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2D – Excessive white smoke.

Action

Interview the driver and verify the complaint.

Engine symptom – Excessive White Smoke and the Engine is Using Coolant?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • See the Coolant Loss – Internal symptom tree.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2D-1 – Excessive white smoke.

Action

Interview the driver and verify the complaint.

Engine symptom – Excessive White Smoke and the Engine is not Using Coolant?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 4 – Fuel System Checks
  • Step 5 – Injector Checks
  • Step 10 – Aftertreatment Checks
  • Step 6 – Air Handling Checks
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2E – Engine speed surge or engine speed unstable.

Action

Interview the driver and verify the complaint.

Engine symptom – Engine Speed Surge or Engine Speed Unstable?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 4 – Fuel System Checks
  • Step 5 – Injector Checks
  • Step 7 – EGR Checks
  • Step 6 – Air Handling Checks
  • Step 8 – Electronics Checks
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2F – Engine will not start or difficult to start.

Action

Interview the driver and verify the complaint.

Engine symptom – Engine Difficult to Start or Will Not Start?
YES NO

Perform the troubleshooting steps that pertain to difficult to start or will not start concerns per the troubleshooting steps in the recommended order listed below:

  • Step 3 – No Start Checks
  • Step 4 – Fuel System Checks
  • Step 5 – Injector Checks
  • Step 6 – Air Handling Checks
  • Step 8 – Electronics Checks
  • Check the engine base timing. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 001-088 in Section 1.
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2G – Engine stalls or shuts off unexpectedly.

Action

Interview the driver and verify the complaint.

Engine symptom – Engine Stalls or Shuts Off Unexpectedly?
YES NO

Perform the troubleshooting steps that pertain to stalls or shuts off unexpectedly per the troubleshooting steps in the recommended order listed below:

  • Step 3 – No Start Checks
  • Step 4 – Fuel System Checks
  • Step 5 – Injector Checks
  • Step 6 – Air Handling Checks
  • Step 8 – Electronics Checks
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure

Guided Step 2H – Engine run-on, or will not shut down.

Action

Interview the driver and verify the complaint.

Engine symptom – Engine Run-On or Slow to Shut Down after operating at high idle for 1 minute then keyed OFF?
YES NO

Perform the troubleshooting steps in the recommended order listed below:

  • Step 5 – Injector Checks
  • Step 4 – Fuel System Checks
  • Step 9 – Base Engine Checks.
 No Repair
Perform the troubleshooting steps suggested in the repair procedure
Return to appropriate symptom tree

Guided Step 3 – No-start troubleshooting procedures.

Guided Step 3A – Verify the fuel system has been primed.

Conditions

  • Turn keyswitch OFF.

Action

Verify the fuel system has been primed.

If entering this tree after a component has been replaced in the fuel system, or after the engine has been run out of fuel, verify the fuel system has been properly primed before proceeding.

Fuel system properly primed?
YES NO
No Repair

Prime the fuel system.

Repair complete

Guided Step 3B – Check fuel shutoff valve voltage.

Conditions

  • Turn keyswitch ON.

Action

Measure the voltage from the fuel shutoff valve post to engine block ground.
SMALL | MEDIUM | LARGE

Fuel shutoff valve voltage greater than 11-VDC?
YES NO
No Repair No Repair

Guided Step 3B-1 – Check ECM keyswitch voltage.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the OEM harness from the ECM.
  • Turn keyswitch ON.

Action

Measure the voltage from the keyswitch input SIGNAL wire of the OEM harness to engine block ground.
SMALL | MEDIUM | LARGE

Keyswitch voltage equal to battery voltage?
YES NO
No Repair

Repair or replace the OEM power harness, or keyswitch, or check the battery connections.

Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-064 in Section 19.

Repair complete

Guided Step 3B-2 – Check the fuel shutoff valve wire.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness from the ECM.
  • Disconnect the fuel shutoff valve wire from the valve terminal post.

Action

Measure the resistance from the fuel shutoff valve SIGNAL pin in the ECM connector to the fuel shutoff valve eyelet.

Use the following procedure for general resistance measurement techniques. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-360 in Section 19.

SMALL | MEDIUM | LARGE

Less than 10 ohms?
YES NO

Call for authorization to replace the ECM. Upon receipt of authorization, replace the ECM. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-031 in Section 19.

Repair or replace the engine harness.

Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-043 in Section 19.

Repair complete

Guided Step 3B-3 – Check the ECM power and ground.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the ECM power supply connector from the ECM.

Action

Measure the voltage from the ECM battery SUPPLY (-) to the ECM battery SUPPLY (+) pins in the ECM power harness connector.
SMALL | MEDIUM | LARGE

ECM battery supply voltage equal to the battery voltage?
YES NO

Call for authorization to replace the ECM. Upon receipt of authorization, replace the ECM. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-031 in Section 19.

No Repair
Repair complete
Repair complete

Guided Step 3C – Check fuel shutoff valve resistance.

Conditions

  • Turn keyswitch OFF.
  • Disconnect fuel shutoff valve SIGNAL wire from the fuel shutoff solenoid.
  • Be sure fuel shutoff valve temperature is between 20°C [68°F] and 25°C [78°F].

Action

Measure the resistance from the fuel shutoff solenoid post to engine block ground.

The fuel shutoff solenoid must be between 20°C [68°F] and 25°C [78°F] before using the resistance specifications listed.

Use the following procedure for general resistance measurement techniques. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-360 in Section 19.

SMALL | MEDIUM | LARGE

Fuel shutoff solenoid resistance:

  • 1 to 5 ohms for 6-VDC solenoids
  • 6 to 15 ohms for 12-VDC solenoids
  • 24 to 50 ohms for 24-VDC solenoids
  • 42 to 80 ohms for 32-VDC solenoids
  • 46 to 87 ohms for 36-VDC solenoids
  • 92 to 145 ohms for 48-VDC solenoids
  • 315 to 375 ohms for 74-VDC solenoids
  • 645 to 735 ohms for 115-VAC solenoids?
YES NO
No Repair

Replace the fuel shutoff solenoid. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-050 in Section 19.

Repair complete

Guided Step 3D – Check fuel shutoff valve actuator.

Conditions

  • Turn keyswitch OFF.
  • Remove the fuel shutoff valve solenoid, valve disc, valve seat, and actuator.

Action

Check the valve disc, valve seat, and actuator disc for dirt, metal debris, bonding separation, corrosion, cracks, or wear.
SMALL | MEDIUM | LARGE

Debris or damage found on the valve disc, valve seat, or actuator disc?
YES NO

Replace the damaged fuel shutoff valve component. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-050 in Section 19.

No Repair
Repair complete

Guided Step 3E – Check for correct priming pump operation, if equipped.

Conditions

  • Turn keyswitch OFF.
  • Assemble fuel shutoff valve components.
  • Turn keyswitch ON.

Action

Listen for lift pump operation after the keyswitch is turned to the ON position.

Not all ISX engines use a priming pump and not all priming pumps actuate at keyswitch ON. Verify the type of pump system on the engine before beginning this step.

Lift pump operates after turning the keyswitch ON or does the engine not use a priming pump?
YES NO
No Repair

Check or replace lift pump. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-045 in Section 5.

Repair complete

Guided Step 3E-1 – Check priming pump pressure.

Conditions

  • Turn keyswitch OFF.
  • Turn keyswitch ON.

Action

Measure the priming pressure at the quick connect fitting located on the top of the integrated fuel system module (IFSM).

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-045 in Section 5.

Pump pressure meets the 69 kPa [10 psi] specification?
YES NO
No Repair No Repair

Replace the lift pump. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-045 in Section 5.

Guided Step 3F – Check for coolant in the EGR transfer tube.

Conditions

  • Turn keyswitch OFF.

Action

Remove the EGR transfer hose from the EGR cooler outlet.

Coolant present in the crossover tube?
YES NO

See the Coolant Loss – Internal symptom tree.

Perform the next troubleshooting procedure as outlined in Step 2
Repair complete

Guided Step 4 – Fuel system checks.

Guided Step 4A – Verify the fuel system has been primed.

Conditions

  • Turn keyswitch OFF.

Action

Verify the fuel system has been primed.

If entering this tree after a component has been replaced in the fuel system, or after the engine has been emptied of fuel, verify the fuel system has been properly primed before proceeding.

Fuel system been properly primed?
YES NO
No Repair

Prime the fuel system.

Repair complete

Guided Step 4B – Check for air in the fuel.

Conditions

  • Operate the engine at low idle (engine cranking if troubleshooting No-Start).

Action

Connect the equipment to the quick-connect fitting at the fuel module as shown.

  • Put a coil in the clear hose.
  • Put the end of the clear hose in a clean container.
  • Operate the engine at low idle with no load.
  • Slightly open the valve until a steady stream of fuel is visible.
SMALL | MEDIUM | LARGE

Air bubbles visible in the coil of clear tubing?
YES NO

Locate and correct the cause of air ingestion in the OEM fuel supply system or damaged fuel filter sealing ring.

With EGR

Check the ECM cooling plate, associated plumbing, and o-ring seals for failures that can cause air ingestion. Repair or replace the malfunctioning component.

 No Repair
Repair complete

Guided Step 4C – Check fuel inlet restriction.

Conditions

  • Connect a vacuum gauge to the suction side Compuchek™ fitting.
  • Turn keyswitch ON.
  • Operate the engine at high idle (engine cranking if troubleshooting No-Start).

Action

If the engine uses a priming pump, wait until after the priming pump has turned off and observe the reading on the vacuum gauge.

Check the fuel inlet restriction.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-020 in Section 6.

SMALL | MEDIUM | LARGE

Fuel inlet restriction less than the specifications listed below?

Dirty – 305 mm-Hg [12 in-Hg]; – New – 203 mm-Hg [8 in-Hg]
YES NO
No Repair

Locate the cause of high fuel inlet restriction. Check the suction-side fuel filter, fuel supply lines, and inlet check valve.

Repair complete

Guided Step 4D – Check drain line restriction.

Conditions

  • Connect pressure gauge, Part Number 3375278.
  • Turn keyswitch ON.
  • Operate the engine at high idle (engine cranking if troubleshooting No-Start).

Action

Observe reading on the pressure gauge.
SMALL | MEDIUM | LARGE

Fuel drain line restriction less than 229 mm-Hg [9 in-Hg]?
YES NO
No Repair

Locate the cause of high fuel drain line restriction in the OEM fuel return line.

Repair complete

Guided Step 4E – Check rail fuel pressure.

Conditions

  • Connect pressure gauge, Part Number 3375932, on the Compuchek™ fitting (as shown).
  • Turn keyswitch ON.
  • Operate the engine at low idle (engine cranking if troubleshooting No-Start).

Action

Read the rail fuel pressure at low idle and high idle.

Read the rail fuel pressure while cranking if the engine will not start.

  • Cranking: greater than 689 kPa [100 psi] at 130 rpm for at least 10 seconds.
  • Low idle: 1589 to 1889 kPa [230 to 274 psi] at 600 rpm.
  • High idle: 1896 to 2068 kPa [275 to 325 psi] at 1800 rpm.
SMALL | MEDIUM | LARGE

Rail fuel pressure meet the specification?
YES NO
No Repair No Repair
Perform the next troubleshooting procedure as outlined in Step 2
with EGR 4E-2

Guided Step 4E-1 – Check the pressure side fuel filter restriction.

Conditions

  • Connect pressure gauge, Part Number 3375932, on the rail fuel pressure Compuchek™ fitting.
  • Connect pressure gauge, Part Number 3375932, on the gear pump output pressure Compuchek™ fitting.
  • Operate the engine at high idle (engine cranking if troubleshooting no-start).

Action

Read the fuel pressure drop across the pressure side fuel filter at high idle or while cranking if the engine will not start.
SMALL | MEDIUM | LARGE

Pressure-side fuel filter pressure drop less than 517 kPa [75 psi]?
YES NO
No Repair

Replace the pressure side fuel filter. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-015 in Section 6.

Repair complete

Guided Step 4E-2 – Check 1724 kPa [250 psi] pressure regulator.

Conditions

  • Turn keyswitch OFF.

Action

Remove the 1724 kPa [250 psi] fuel pressure regulator.

  • Inspect for debris or damage or incomplete sealing of the regulator.
SMALL | MEDIUM | LARGE

1724 kPa [250 psi] pressure regulator free of debris or damage?
YES NO
No Repair

Replace 1724 kPa [250 psi] regulator.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-073 in Section 5.

Repair complete

Guided Step 4E-3 – Check 2206 kPa [320 psi] or 2620 kPa [380 psi] pressure regulator.

Conditions

  • Turn keyswitch OFF.

Action

Remove the 2206 kPa [320 psi] fuel pressure regulator.

  • Inspect for debris, damage, or incomplete sealing of the regulator.
SMALL | MEDIUM | LARGE

Pressure regulator free of debris or damage?
YES NO

Replace the gear pump module.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-016 in Section 5.

Replace 2620 kPa [380 psi] regulator.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 005-073 in Section 5.

Repair complete
Repair complete

Guided Step 5 – Injector and Actuator Diagnostics.

Guided Step 5A – Perform the injector check valve leak test.

Action

Perform the injector check valve leak test to check for internal injector check valve damage.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-026 in Section 6.

Injector leak test detects a leaking injector?
YES NO

Replace the leaking injector. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-026 in Section 6.

No Repair
Repair complete

Guided Step 5B – Perform INSITE™ electronic service tool Cylinder Performance Test.

Conditions

  • Troubleshoot any active fault codes before performing the test.
  • Note that engine coolant temperature must be greater than 83°C [180°F].
  • Connect INSITE™ electronic service tool.
  • Idle engine.

Action

Perform the INSITE™ electronic service tool Cylinder Performance Test.

During the initial 30 seconds of the Cylinder Performance Test, INSITE™ electronic service tool is checking to make sure all parameters have been met to enter the test.

Once the initial Pass or Fail reading is displayed, the test is live for the next 2 minutes. Monitor the display to see if cylinders or banks drop out during this 2 minute window. A cylinder can switch from pass to fail and back to pass quickly, so monitor the screen closely.

INSITE™ electronic service tool Cylinder Performance Test identifies a single malfunctioning injector?
YES NO
No Repair No Repair

Guided Step 5B-1 – Perform INSITE™ electronic service tool Cylinder Performance Test at 600 rpm.

Conditions

  • Troubleshoot any active fault codes before performing the test.
  • Note that engine coolant temperature must be greater than 83°C [180°F].
  • Connect INSITE™ electronic service tool.
  • Idle engine at 600 rpm.

Action

Skip this step and move on to step 5B-2 if the rpm value is the same as that used in step 5B.

Adjust the low speed to 600 rpm and perform INSITE™ electronic service tool Cylinder Performance Test.

During the initial 30 seconds of the Cylinder Performance Test, INSITE™ electronic service tool is checking to make sure all parameters have been met to enter the test.

Once the initial Pass or Fail reading is displayed, the test is live for the next 2 minutes. Monitor the display to see if cylinders or banks drop out during this 2 minute window. A cylinder can switch from pass to fail and back to pass quickly, so monitor the screen closely.

INSITE™ electronic service tool Cylinder Performance Test identifies a single malfunctioning injector?
YES NO
No Repair No Repair

Guided Step 5B-2 – Perform INSITE™ electronic service tool Cylinder Performance Test at 700 rpm.

Conditions

  • Troubleshoot any active fault codes before performing the test.
  • Note that engine coolant temperature must be greater than 83°C [180°F].
  • Connect INSITE™ electronic service tool.
  • Idle engine at 700 rpm.

The idle speed may need to be adjusted to perform this test. Toggle the cruise control increment/decrement switch to see if the idle speed can be adjusted. If not, use INSITE™ electronic service tool to either enable the Adjustable Low Idle Speed feature or adjust the Low Idle Speed.

Action

Skip this step and move on to step 5B-3 if the RPM value is the same as that used in step 5B.

Adjust the low speed to 700 rpm and perform INSITE™ electronic service tool Cylinder Performance Test.

During the initial 30 seconds of the Cylinder Performance Test, INSITE™ electronic service tool is checking to make sure all parameters have been met to enter the test.

Once the initial Pass or Fail reading is displayed, the test is live for the next 2 minutes. Monitor the display to see if cylinders or banks drop out during this 2 minute window. A cylinder can switch from pass to fail and back to pass quickly, so monitor the screen closely.

INSITE™ electronic service tool Cylinder Performance Test identifies a single malfunctioning injector?
YES NO
No Repair No Repair

Guided Step 5B-3 – Perform INSITE™ electronic service tool Cylinder Performance Test at 800 rpm.

Conditions

  • Troubleshoot any active fault codes before performing the test.
  • Note that engine coolant temperature must be greater than 83°C [180°F].
  • Connect INSITE™ electronic service tool.
  • Idle engine at 800 rpm.

The idle speed may need to be adjusted to perform this test. Toggle the cruise control increment/decrement switch to see if the idle speed can be adjusted. If not, use INSITE™ electronic service tool to either enable the “Adjustable Low Idle Speed” feature or adjust the Low Idle Speed.

Action

Skip this step and move on to step 5C if the rpm value is the same as that used in step 5B.

Adjust the low speed to 800 rpm and perform INSITE™ electronic service tool Cylinder Performance Test.

During the initial 30 seconds of the Cylinder Performance Test, INSITE™ electronic service tool is checking to make sure all parameters have been met to enter the test.

Once the initial Pass or Fail reading is displayed, the test is live for the next 2 minutes. Monitor the display to see if cylinders or banks drop out during this 2 minute window. A cylinder can switch from pass to fail and back to pass quickly, so monitor the screen closely.

INSITE™ electronic service tool Cylinder Performance Test identifies a single malfunctioning injector?
YES NO
No Repair No Repair

Guided Step 5C – Perform INSITE™ electronic service tool Cylinder Cutout Test

Conditions

  • Turn OFF air conditioning.
  • Turn OFF fan.
  • Disable any electrical loads.
  • Idle engine at the engine speed at which the misfire is present.

Action

Perform INSITE™ electronic service tool cylinder cutout test.

A failing cylinder will have no effect on engine sound and operation when cut out using this test.

All cylinders pass the cylinder cutout test?
YES NO
No Repair No Repair

Guided Step 5C-1 – Perform INSITE™ electronic service tool cylinder cutout test on individual injector banks.

Conditions

  • Turn OFF air conditioning.
  • Turn OFF fan.
  • Disable any electrical loads.
  • Engine idling at the engine speed at which the misfire is present.

Action

Perform INSITE™ electronic service tool cylinder cutout test.

  • Operate the engine on the front bank of injectors identified by the cylinder cutout test by disabling the rear three cylinders 4, 5, 6 cylinders with INSITE™ electronic service tool.
  • Operate the engine on the rear bank of injectors identified by the Cylinder Performance Test by disabling the front three cylinders (1,2,3) with INSITE™ electronic service tool.
  • To disable one bank of cylinders with INSITE™ electronic service tool, click on the cylinder numbers associated with that bank. The front bank consists of cylinders 1, 2, and 3 and the rear bank is cylinders 4, 5, and 6.
  • A malfunctioning bank of injectors will cause the engine to run poorly when the opposite bank is cut out using this test.

Malfunctioning bank of injectors isolated by operating the engine on either bank of injectors?
YES NO
No Repair No Repair

Guided Step 5C-2 – Perform INSITE™ electronic service tool Cylinder Cutout Test single cylinder operation.

Conditions

  • Turn OFF air conditioning.
  • Turn OFF fan.
  • Disable any electrical loads.
  • Idle engine at the engine speed at which the misfire is present.

Action

Perform INSITE™ electronic service tool cylinder cut out test.

Operate the engine on the cylinder identified by the Cylinder Performance Test by disabling five cylinders with INSITE™ electronic service tool and only operating on the suspect cylinder.

To disable five cylinders with INSITE™ electronic service tool, click on the cylinder numbers until only one cylinder is enabled.

The engine should roughly maintain idle speed when operating on a single cylinder. A weak or misfiring cylinder will be detected if the engine dies or can not maintain idle speed when operating on a single cylinder.

Continue testing all six cylinders by operating the engine on each individual injector.

If the engine will not run on one cylinder regardless of the cylinder selected, increase the idle RPM and retest.

Do not run the engine on one cylinder for an extended period of time.

Malfunctioning injector isolated by operating the engine on a single injector?
YES NO
No Repair No Repair

Guided Step 5C-3 – Verify overhead adjustments are correct for the suspected malfunctioning injector.

Conditions

Action

Measure the overhead settings for the suspected malfunctioning injector.

  • Check the valve lash and injector pre-load torque before replacing the injector.
  • Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 003-004 in Section 3.

Overhead settings within the reset limits outlined in Procedure 003-004?
YES NO

Replace the malfunctioning injector.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-026 in Section 6.

Adjust the overhead settings.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 003-004 in Section 3.

Perform the Cylinder Performance Test to determine if a misfire still exists after adjusting the overhead settings.
Repair complete

Guided Step 5D – Swap the front and rear metering actuators.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness from the timing and metering actuators.

Action

Swap the front and rear metering actuators to determine if the malfunctioning bank of cylinders follows a specific metering actuator.

  • Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-110 in Section 19.
  • Perform INSITE™ electronic service tool Cylinder Performance Test.

Cylinder performance test finds a malfunctioning bank?
YES NO

Replace the malfunctioning metering actuator.

 No Repair
Repair complete

Guided Step 5E – Swap the front and rear timing actuators

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness from the timing and metering actuators.

Action

Swap the front and rear timing actuators to determine if the malfunctioning bank of cylinders follows a specific timing actuator.

  • Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-111 in Section 19.
  • Perform INSITE™ electronic service tool Cylinder Performance Test.

Malfunctioning bank follows the timing actuator?
YES NO

Replace the timing actuator.

Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-111 in Section 19.

No Repair
Repair complete

Guided Step 5F – Monitor the engine percent load value with INSITE™ electronic service tool. (Perform this step for troubleshooting low power only.)

Conditions

  • Connect INSITE™ electronic service tool.
  • Idle the engine at operating temperature.
  • Operate engine at no load.

Action

Monitor the engine percent load value with INSITE™ electronic service tool with the engine running at idle.

Engine percent load value consistently above 8 percent?
YES NO

Replace both metering actuators. Use the following procedure in the CM871 and CM876 Electronic Control Systems, ISX and ISM Engines Troubleshooting and Repair Manual, Bulletin 4021560. Refer to Procedure 019-110 in Section 19.

No Repair
Repair complete
Perform the next troubleshooting procedure as outlined in Step 2

Guided Step 6 – Air handling diagnostic checks.

Guided Step 6A – Start the engine and read the fault codes.

Conditions

  • Connect INSITE™ electronic service tool.
  • Operate engine at low idle.

Action

Check the fault codes with the engine running.

  • Use INSITE™ electronic service tool to read the fault codes.

Active fault codes?
YES NO
No Repair No Repair
Go to appropriate fault code troubleshooting tree

Guided Step 6B – Check air intake restriction.

Conditions

  • Turn keyswitch ON.
  • Run engine at advertised horsepower and rpm.

Action

Check the intake system restriction by installing a vacuum gauge or water manometer into the air intake system.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-031 in Section 10.

SMALL | MEDIUM | LARGE

Air intake restriction greater than 635 mm-H2O [25 in-H2O] for a used air filter or 254 mm-H2O [10 in-H2O] for a new filter?
YES NO

Correct the cause of high intake air restriction.

Check for a plugged air filter or restricted air intake piping.

 No Repair
Repair complete

Guided Step 6C – Inspect the charge-air cooler

Conditions

  • Turn keyswitch OFF.

Action

Pressure test the charge-air cooler.
SMALL | MEDIUM | LARGE

Pressure drop 34 kPa [5 psi] or less in 15 seconds?
YES NO
No Repair

Repair the charge-air cooler assembly. Refer to the OEM service manual.

Repair complete

Guided Step 6D – Inspect the turbocharger blades for damage.

Conditions

  • Turn engine OFF.
  • Remove intake and exhaust connections from turbocharger.

Action

Inspect the compressor and turbine fins for damage or wear.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-033 in Section 10.

Damage found on turbocharger blades?
YES NO

Replace the turbocharger.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-033 in Section 10.

No Repair
Repair complete

Guided Step 6E – Inspect the turbocharger shaft movement.

Conditions

  • Turn keyswitch OFF.
  • Remove VGT actuator from the turbocharger.

Action

Inspect the sector gear on the turbocharger for damaged or broken gear teeth.

Move the sector gear lever on the turbocharger bearing housing up and down from stop to stop. Check for smooth movement between the stops.

There will be an initial friction force that must be overcome before the actuator lever will move. Once movement is started, the actuator lever should move to the other stop position by hand.

Use the following procedure in the Signature™, ISX and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-134 in Section 10.

Nozzle slides evenly from stop to stop and gear teeth undamaged?
YES NO

Install the turbocharger actuator.

Use the following procedure in the Signature™, ISX and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-134 in Section 10.

A turbocharger mechanical malfunction has been detected.

This malfunction may have been caused by debris exiting the engine, causing the turbocharger nozzle to stop moving. Inspect the base engine components for damage.

Inspect the turbocharger for repair and reuse, if possible. Use the following procedure in the Signature™, ISX and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 010-145 in Section 10.

Perform new troubleshooting procedure as outlined in Step 2.
Repair complete

Guided Step 7 – Check EGR valve for proper operation.

Guided Step 7A – Check for EGR-related fault codes

Conditions

  • Turn keyswitch OFF.
  • Wait 30 seconds.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.

Action

Check for any EGR-related fault codes.

EGR-related fault codes present?
YES NO

Troubleshoot electronic fault codes.

 No Repair
Appropriate fault code troubleshooting trees

Guided Step 7B – Check for inactive EGR differential pressure sensor fault codes.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.

Action

Check for active fault codes.

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 1866, 2273, or 2274 active?
YES NO
No Repair No Repair
Appropriate fault code troubleshooting tree

Guided Step 7C – Check the EGR differential pressure tubes for leaks.

Conditions

  • Note leaks by traces of soot.

Action

Check the lines for leaks.

Leaks detected at either the low or high EGR differential pressure tubes?
YES NO

Tighten the fittings or replace the EGR differential pressure tube.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-026 in Section 11.

No Repair
Repair complete

Guided Step 7D – Check the EGR differential pressure sensor adapter for leaks.

Conditions

  • Turn keyswitch OFF.

Action

Inspect the EGR differential pressure sensor adapter for leaks.

  • Leaks will be easily noted by traces of soot. If necessary remove the sensor to inspect the o-rings between the EGR differential pressure sensor and the adapter for proper sealing. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-028 in Section 11.

Leaks detected at the EGR differential pressure sensor adapter?
YES NO

Replace the EGR differential pressure sensor adapter.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-028 in Section 11.

No Repair
Repair complete

Guided Step 7E – Check the EGR differential pressure tubes for plugging.

Conditions

  • Turn keyswitch OFF.
  • Remove the EGR differential pressure tubes.

Action

Inspect the EGR differential pressure tubes for restrictions, soot plugging, and plugging.

Debris or soot found in either EGR differential pressure tube?
YES NO

Clear the debris or replace the EGR differential pressure tube.

Remove the exhaust aftertreatment system from the vehicle and inspect for reuse.

 No Repair
Repair complete

Guided Step 7F – Check for air leaks in the EGR system.

Action

Check for leaks in the EGR connection tubing and connections.

Soot streaks are noticeable where leaks are present.

Leaks found in the EGR connection tubing?
YES NO

Repair any leaks in the EGR system.

 No Repair
Repair complete
Perform the next troubleshooting procedure as outlined in Step 2

Guided Step 8 – Verify electronic features operating correctly.

Guided Step 8A – Verify accelerator pedal travel.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.

Action

With INSITE™ electronic service tool, monitor accelerator pedal while fully depressing and releasing the accelerator pedal.

Accelerator pedal reads 0 percent when the accelerator is released and 100 percent when the accelerator is depressed?
YES NO
No Repair

Determine and correct the cause of accelerator pedal restriction.

Repair complete

Guided Step 8B – Monitor vehicle speed.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Start the engine.

Action

With INSITE™ electronic service tool, monitor vehicle speed while the vehicle is not moving.

Vehicle speed reads 0 when the vehicle is not moving?
YES NO
No Repair

Check the vehicle speed sensor and circuit or locate the cause of the vehicle speed interference.

Repair complete

Guided Step 8C – Verify electronic feature settings are correct.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.

Action

With INSITE™ electronic service tool, verify the following adjustable parameters are correctly set:

  • Maximum vehicle speed
  • Powertrain protection
  • Rear axle ratio
  • Number of transmission tailshaft gear teeth
  • Tire revolutions per mile
  • Gear-down protection
  • Cruise control droop settings
  • Cruise control maximum vehicle speed.

Electronic features set correctly?
YES NO
No Repair

Correct programmable features.

Repair complete

Guided Step 8D – Check the ambient air pressure sensor accuracy

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.

Action

Check for correct barometric pressure sensor readings.

  • Compare the barometric pressure sensor reading in INSITE™ electronic service tool data monitor/logger to the present local barometric pressure.

Barometric pressure sensor reading in INSITE™ electronic service tool within 5 percent of the present local barometric pressure reading?
YES NO
No Repair

Replace the barometric pressure sensor. Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-004 in Section 19.

Repair complete

Guided Step 8E – Check the intake manifold pressure sensor accuracy.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Start and operate the engine at high idle after connecting the mechanical intake manifold pressure gauge.

Action

Connect a mechanical intake manifold pressure gauge to the engine, as close to the intake manifold pressure sensor as possible.

  • Start INSITE™ electronic service tool Data Monitor/Logger and compare INSITE™ electronic service tool reading for intake manifold pressure to the mechanical gauge.

INSITE™ electronic service tool reading within 17 kPa [2.5 psi] of mechanical gauge reading?
YES NO
No Repair

Remove and clean the intake manifold pressure sensor.

Use the following procedure found in the ISX CM871 and ISM CM876 Electronic Control System, Bulletin 4021560. Refer to Procedure 019-159 in Section 19.

Perform the next troubleshooting procedure as outlined in Step 2

Repair complete

Guided Step 9 – Perform base engine mechanical checks.

Guided Step 9A – Verify injection timing is correct.

Conditions

  • Turn keyswitch OFF.
  • Remove valve cover.

Action

Verify injection timing is correct.

Measure the injection timing. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 006-025 in Section 6.

If the injection timing is found to be out of specification, bart the engine to “insert pin” and install the crankshaft pin. Install the appropriate injector camshaft wedge to set the correct injection timing. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 001-088 in Section 1.

Injection timing correct?
YES NO
No Repair

Correct the injection timing.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 001-088 in Section 1.

Repair complete

Guided Step 9B – Verify overhead adjustments are correct.

Conditions

  • Turn keyswitch OFF.
  • Remove valve cover.

Action

Measure the overhead settings.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 003-004 in Section 3.

Overhead settings within the reset limits?
YES NO
No Repair

Adjust the overhead settings.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 003-004 in Section 3.

Repair complete

Guided Step 9C – Verify engine brake adjustment.

Conditions

  • Turn keyswitch OFF.
  • Remove valve cover.

Action

Verify the engine brakes are operating correctly.

Engine brake settings within the reset limits?
YES NO
No Repair

Adjust the engine brake settings.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 020-004 in Section 20.

Repair complete

Guided Step 9D – Verify crankshaft tone wheel is not loose.

Conditions

  • Unplug the crankshaft position sensor.
  • Operate the engine at idle.

Action

Operate the engine with the crankshaft position sensor unplugged and identify if idle quality improves.

  • If idle quality improves, remove the oil pan and inspect the crankshaft tone wheel to see if it is loose.

Crankshaft tone wheel loose?
YES NO

Repair the tone wheel.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 001-069 in Section 1.

No Repair
Repair complete

Guided Step 9E – Check exhaust restriction.

Conditions

  • Install a pressure gauge into the exhaust system.
  • Turn keyswitch ON.
  • Run engine at advertised horsepower and rpm.

Action

Check exhaust restriction by installing a pressure gauge into the exhaust system just past the turbocharger outlet.

If a port is not found in the exhaust system, remove the exhaust gas temperature 1 sensor and install the pressure gauge in the temperature sensor port.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-009 in Section 11.

SMALL | MEDIUM | LARGE

Exhaust restriction greater than 305 mm-Hg [12.0 in-Hg]?
YES NO

Remove the exhaust aftertreatment system from the vehicle and inspect for reuse. Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-050 in Section 11.

No Repair
Repair complete

Guided Step 9F – Verify engine blowby is within specification.

Conditions

  • Turn keyswitch OFF.
  • Connect the appropriate orifice to the end of the blowby draft tube.
  • Start engine.

Action

Load engine to rated rpm on a chassis dynamometer.

Measure the engine blowby.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 014-010 in Section 14.

Engine blowby measurements within specification?
YES NO
No Repair

Engine may need to be rebuilt. See the engine specifications.
Perform the next troubleshooting procedure as outlined in Step 2
Repair complete

Guided Step 10 – Aftertreatment checks.

Guided Step 10A – Check for aftertreatment-related fault codes.

Conditions

  • Turn keyswitch OFF.
  • Connect INSITE™ electronic service tool.

Action

Use INSITE™ electronic service tool to read the fault codes.

Check for any aftertreatment fault codes, specifically fault codes related to high soot in the aftertreatment particulate trap, face plugging of the aftertreatment catalyst, and aftertreatment catalyst efficiency.

Fault codes related to the aftertreatment system found to be active?
YES NO
No Repair No Repair
Appropriate fault code troubleshooting tree

Guided Step 10B – Perform basic aftertreatment troubleshooting checks.

Action

The following items must be checked or verified before continuing:

  • Check to make sure that Ultra Low Sulfur Diesel fuel is being used in the vehicle.
  • Check for any fuel leaks around the aftertreatment fuel shutoff valve or aftertreatment injector components.
  • Check for any noticeable exhaust leaks around any aftertreatment components.
  • Check the exhaust pipes for restrictions that can create high exhaust back pressure.
  • Check the aftertreatment sensors, wires, connectors, and harnesses for proper connections.
  • Check the exhaust gas filter differential pressure sensor tubes for proper connections.

All parts inspected and appear to be functioning properly?
YES NO
No Repair

Correct the damage and verify the complaint is no longer present after repair.

Repair complete

Guided Step 10C – Check for signs of internal damage to the aftertreatment system.

Conditions

  • Operate engine to normal operating temperature.
  • Be sure the vehicle is stationary.

Action

Quickly snap the throttle pedal accelerating the engine from low idle to high idle while checking for smoke at the exhaust outlet.

Inspect for the following during the snap throttle acceleration.

  • Smoke (any color) coming out of the vehicle tailpipe.
  • Soot or signs of fuel, coolant, or oil inside the tailpipe.

If the aftertreatment system is operating correctly, no visible smoke will be present during the snap throttle acceleration. Any visible smoke is an indication of a possible malfunction in the aftertreatment system.

Visible smoke (black or white) present during the snap throttle acceleration?
YES NO

Damage in the aftertreatment system.

Remove the exhaust gas aftertreatment system from the vehicle and inspect for reuse.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-050 in Section 11.

No Repair
Repair complete. Troubleshoot the smoke complaint, use the proper TT tree steps

Guided Step 10D – Check exhaust restriction.

Conditions

  • Install a pressure gauge into the exhaust system.
  • Turn keyswitch ON.
  • Operate engine at advertised horsepower and rpm.

Action

Check exhaust restriction by installing a pressure gauge into the exhaust system just past the turbocharger outlet.

If a port is not found in the exhaust system, remove the exhaust gas temperature 1 sensor and install the pressure gauge in the temperature sensor port.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-009 in Section 11.

SMALL | MEDIUM | LARGE

Exhaust restriction greater than 305 mm-Hg [12.0 in-Hg]?
YES NO

Remove the exhaust aftertreatment system from the vehicle and inspect for reuse.

Use the following procedure in the Signature™, ISX, and QSX15 Service Manual, Bulletin 3666239. Refer to Procedure 011-049 in Section 11.

No Repair
Repair complete
Perform the next troubleshooting procedure as outlined in Step 2
Last Modified:  11-Jul-2011
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Published by Jack

Hello, I'm Jack, a diesel engine fan and a blogger. I write about how to fix and improve diesel engines, from cars to trucks to generators. I also review the newest models and innovations in the diesel market. If you are interested in learning more about diesel engines, check out my blog and leave your feedback.