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CM870 and ISX Engines – CM870 Electronic Control System Signature and ISX Engines – Troubleshooting and Repair Manual

Fuel Economy Troubleshooting Tree

Symptoms

    • Fuel Consumption Excessive.

How To Use This Tree

This symptom tree is to be used to troubleshoot fuel economy complaints. This tree is used along with the Fuel Consumption – Customer Complaint Form and the Driveability Low Power/Excessive Fuel – Consumption Checklist to help isolate engine, chassis, or driver issues associated with excessive fuel consumption.

Shop Talk

The Fuel Consumption – General Information section of the Troubleshooting and Repair Manual, Signature, ISX, QSX15 Engines, Bulletin 3666239 and Troubleshooting Excessive Fuel Consumption, Bulletin 3666094, should be referenced prior to any troubleshooting being performed on a customer’s engine.

NOTE: Prior to running the INSITE™ electronic service tool EGR Valve and EGR Valve/Turbocharger Operational Test, the ECM Calibration Software Phase could possibly need to be updated to the latest Software Phase. The ECM Calibration Phase Software can be checked in INSITE™ electronic service tool, under ‘Features and Parameters’. Expand the selection for ‘System ID and Dataplate’ and go to ‘Calibration Information’. If the Software Phase is earlier than shown below, recalibrate the ECM using the January 2006 INCAL™ CD-ROM, or later. Engines with the Software Phase listed below or later do not require a recalibration.

ISX engines with CM870 (engines built after January 2004) require Software Phase 06050302.

ISX engines with CM870 (engines built before January 2004) require no changes at this time.

This is a warrantable calibration change.

The cause of excessive fuel consumption is difficult to diagnose and correct because of the potential number of factors involved. Actual fuel consumption problems can be caused by any of the following factors:

  • Engine factors
  • Vehicle factors and specifications
  • Environmental factors
  • Driver technique and operating practices
  • Fuel system factors
  • Low power or driveability problems.

Before troubleshooting, it is important to determine the exact complaint. Is the complaint based on whether the problem is real or perceived, or does not meet driver expectations? The Fuel Consumption – Customer Complaint Form is a valuable list of questions that can be used to assist the service technician in determining the cause of the problem. Complete the form before troubleshooting the complaint. The following are some of the factors that must be considered when troubleshooting fuel consumption complaints.

  • Excessive Idling Time: Idling the engine can use from 0.5 to 1.5 gallons per hour depending on the engine idle speed.
  • Vehicle Aerodynamics: The largest single power requirement for a truck is the power needed to overcome air resistance. As a general rule, each 10 percent reduction in air resistance results in a 5 percent increase in mile per gallon.
  • Rolling Resistance: Rolling resistance is the second largest consumer of power on a truck. The type of tire and tread design have a sizeable effect on fuel economy and performance. Changing from a bias ply to a low profile radial tire can reduce rolling resistance by about 36 percent.
  • Environmental and Seasonal Weather Changes: As a general rule, there can be as much as 1 to 1.5 mile per gallon difference in fuel consumption, depending on the season and the weather conditions.
  • Truck Route and Terrain: East and west routes experience almost continual crosswinds and head winds. Less fuel can be used on north and south routes where parts of the trip are not only warmer, but see less wind resistance.
  • Driver Technique and Operating Practices: As a general rule, a 1 mile per hour increase in road speed equals a 0.1 mile per gallon increase in fuel consumption. This means that increasing road speed from 50 to 60 mph will result in a loss of fuel mileage of 1 mpg.
  • Result of a low power or driveability problem: An operator will change driving style to compensate for a low power or driveability problem. Some things the driver is likely to do are (a) shift to a higher engine rpm or (b) run on the droop curve in a lower gear instead of upshifting to drive at part-throttle conditions. These changes in driving style will increase the amount of fuel used.

Additional vehicle factors, vehicle specifications, and axle alignment can also affect fuel consumption. For additional information on troubleshooting fuel consumption complaints, refer to Troubleshooting Excessive Fuel Consumption, Bulletin 3387245.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Verify the complaint.  
  STEP 1A. Fill out the Fuel Consumption – Customer Complaint Form.
  STEP 1B. Run VE/VMS™.
STEP 2. Electronic checks using INSITE™ electronic service tool.  
  STEP 2A. Check for fault codes.
  STEP 2B. Confirm Features and Parameters.
  STEP 2C. Check the ECM calibration.
  STEP 2D. Monitor vehicle speed.
  STEP 2D-1. Inspect the engine and chassis grounds.
STEP 3. Fuel system inspection.  
  STEP 3A. Inspect the vehicle for fuel leaks.
  STEP 3B. Check the fuel inlet restriction.
  STEP 3C. Check the drain line restriction.
  STEP 3D. Check the fuel grade.
  STEP 3E. Perform the INSITE™ electronic service tool Cylinder Performance Test.
  STEP 3E-1. Interpret the results of the Cylinder Performance Test.
  STEP 3E-2. Interpret the results of the Cylinder Performance Test.
  STEP 3E-3. Measure the resistance between the actuator and the actuator base.
  STEP 3E-4. Swap the front and rear fueling actuators.
  STEP 3E-5. Swap the front and rear timing actuators.
STEP 4. Check the air handling system.  
  STEP 4A. Check the air intake restriction.
  STEP 4B. Pressure test the charge air cooler.
  STEP 4C. Inspect the charge air cooler.
  STEP 4D. Check the exhaust restriction.
STEP 5. Air handling diagnostic checks.  
  STEP 5A. Start the engine and read the fault codes.
  STEP 5B. Inspect the turbocharger blades.
  STEP 5C. Determination of turbocharger type.
  STEP 5D. Check the variable geometry actuator rod for correct travel.
  STEP 5D-1. Check for air leaks and inspect air lines.
  STEP 5D-2. Check the engine and vehicle grounds.
  STEP 5D-3. Check for air pressure at the turbocharger control valve outlet.
  STEP 5D-4. Check for air pressure at the turbocharger control valve outlet.
  STEP 5D-5. Check for correct turbocharger actuator travel.
  STEP 5D-6. Check for air pressure at the turbocharger control shutoff valve outlet.
  STEP 5D-7. Check for air pressure at the turbocharger control shutoff valve inlet.
  STEP 5D-8. Check for plugged turbocharger control shutoff valve filter.
  STEP 5E. Perform the INSITE™ electronic service tool EGR Valve/Turbocharger Operational Test.
  STEP 5E-1. Check the engine and vehicle grounds.
  STEP 5F. Inspect the wastegate actuator hose.
  STEP 5G. Inspect the wastegate actuator rod for travel.
  STEP 5G-1. Inspect the wastegate actuator rod for travel.
  STEP 5H. Measure the resistance of the four-stage wastegate controllers, if equipped.
  STEP 5I. Inspect the four-stage wastegate controller, if equipped.
STEP 6. Base engine checks.  
  STEP 6A. Verify the overhead adjustments are correct.
  STEP 6B. Verify the dipstick calibration.
  STEP 6C. Analyze the engine oil.
  STEP 6D. Check for internal engine damage.

Guided Step 1 – Verify the complaint.

Guided Step 1A – Fill out the Fuel Consumption – Customer Complaint Form.

Action

Fill out the Fuel Consumption – Customer Complaint Form in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Is the problem caused by vehicle factors, environmental factors, or driver technique?
YES NO
No Repair No Repair
Repair complete

Guided Step 1B – Run VE/VMS™.

Action

Fill out the Driveability/Low Power/Excessive Fuel Consumption – Checklist in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 engines, Bulletin 3666239.

Use the data gathered to run VE/VMS™ or provide the data to the appropriate support personnel to run VE/VMS™.

NOTE: VE/VMS™ does not account for adverse ambient conditions.

Taking into consideration the adverse effect of ambient conditions, does the VE/VMS™ fuel economy conflict with the customer’s current fuel economy?
YES NO
No Repair

Explain to the customer the effects of driving habits and vehicle set up on fuel consumption.

See Shop Talk for specific examples of how fuel economy can be affected based on driving habits and vehicles set up.

Repair complete

Guided Step 2 – Electronic checks using INSITE™ electronic service tool.

Guided Step 2A – Check for fault codes.

Conditions

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

Action

Use INSITE™ to read the fault codes.

Are there any active or high counts of inactive fault codes?
YES NO
No Repair No Repair
Troubleshoot fault codes.

Guided Step 2B – Confirm features and parameters.

Conditions

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

Action

Confirm the Programmable Features and Parameters are set correctly.

Verify the following features and parameters:

  • Maximum Cruise Control Speed
  • Cruise Control Upper Droop
  • Cruise Control Lower Droop
  • Gear-Down Maximum Vehicle Speed (Heavy Engine Load) = (peak horsepower rpm x 60 min/hr) / (Gear Down Transmission Gear Ratio x Rear Axle Ratio x Tire Size)
  • Gear-Down Maximum Vehicle Speed (Light Engine Load ) = (peak torque rpm x 60 min/hr) / (Top Gear Transmission Gear Ratio x Rear Axle Ratio x Tire Size)
  • Maximum Accelerator Vehicle Speed
  • Road Speed Governor Upper Droop
  • Road Speed Governor Lower Droop.

NOTE: Refer to the Feature Help Description in INSITE™ electronic service tool for additional information.

Are the features and parameters set correctly?
YES NO
No Repair

Reset the Features and Parameters to the appropriate values.

Repair complete

Guided Step 2C – Check the ECM calibration.

Conditions

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

Action

Compare the ECM Code with the engine rating and CPL. Verify the calibration is correct.

Use the calibration notes field in INSITE™ electronic service tool to confirm the calibration is correct for the application and CPL.

Verify the calibration is not set up for STx, LBSC, or Multiplexing if the application does not require it.

Is the calibration correct?
YES NO
No Repair

Recalibrate the ECM with the correct ECM Code.

Repair complete

Guided Step 2D – Monitor vehicle speed.

Conditions

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

Action

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

Does vehicle speed read zero when the vehicle is not moving and the engine is running?
YES NO
No Repair No Repair

Guided Step 2D-1 – Inspect the engine and chassis grounds.

Conditions

  • Turn keyswitch OFF.

Action

Check for loose or corroded engine, chassis, or battery ground connections.

  • Check the engine ground connection.
  • Check the chassis ground connections.
  • Check the battery terminal connections.

Are all grounds present, properly grounded, free of corrosion, and tight?
YES NO

Check the VSS and the VSS circuit.

Refer to Procedure 019-090, 019-091, or 019-092 in the Troubleshooting Manual, Signature Fuel System, Signature Engines, Bulletin 3666259.

Replace, clean, or tighten the grounds.
Repair complete
Repair complete

Guided Step 3 – Fuel system inspection.

Guided Step 3A – Inspect the vehicle for fuel leaks.

Conditions

  • Turn keyswitch OFF.

Action

Check the suction fuel lines, OEM fuel connections, suction-side fuel filter, fuel pump, IFSM, and actuators for leaks.

With EGR

Check the pressure-side fuel filter, fittings, and hoses to and from the ECM, cooling plate, fuel pump, IFSM, and actuators for leaks.

NOTE: Dye can be placed in the fuel to assist in finding fuel system leaks.

Are any leaks present?
YES NO

Repair or replace the failed component.

 No Repair
Repair complete

Guided Step 3B – Check the fuel inlet restriction.

Conditions

  • Connect vacuum gauge to the suction-side Compucheck® fitting.
  • Turn keyswitch ON.
  • Engine running at high idle.

Action

If the engine uses a fuel lift pump, wait until after priming pump has turned off and observe the reading on the vacuum gauge.
SMALL | MEDIUM | LARGE

Is 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 and fuel supply lines.

Repair complete

Guided Step 3C – Check the drain line restriction.

Conditions

  • Connect pressure gauge, Part Number 3375278.
  • Turn keyswitch ON.
  • Engine running at high idle.

Action

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

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

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

Repair complete

Guided Step 3D – Check the fuel grade.

Conditions

  • Turn keyswitch OFF.

Action

Verify the fuel grade used is appropriate for the application and ambient conditions and fuel quality is acceptable.

Run the engine on an alternate, known good fuel source and verify engine performance if the fuel can not be tested appropriately.

NOTE: Refer to Fuel for Cummins Engines, Bulletin 3379001.

Is the fuel grade used and the quality acceptable?
YES NO
No Repair

Instruct the driver or owner to refuel with acceptable fuel.

Repair complete

Guided Step 3E – Perform the INSITE™ electronic service tool Cylinder Performance Test.

Conditions

  • Connect INSITE™ electronic service tool.
  • Engine running at low idle.

Action

Perform the INSITE™ Cylinder Performance Test.

NOTE: Do not run the engine above 900 rpm when performing the Cylinder Performance Test.

Do all injectors and both banks pass the Cylinder Performance Test?
YES NO
No Repair No Repair

Guided Step 3E-1 – Interpret the results of the Cylinder Performance Test.

Action

Interpret the results of the INSITE™ Cylinder Performance Test.

  • If the Cylinder Performance Test displays bar graphs for each cylinder’s contribution, use the INSITE™ electronic service tool help file to interpret the results.
  • If the Cylinder Performance Test displays pass or fail for each cylinder, run the test at least 3 times to verify the results. Read the Test Results under the Results section of the test.

Did the Cylinder Performance Test find an individual failed cylinder?
YES NO

Replace the failed injector.

Refer to Procedure 006-026 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

 No Repair
Repair complete

Guided Step 3E-2 – Interpret the results of the Cylinder Performance Test.

Action

Interpret the results of the INSITE™ Cylinder Performance Test.

  • If the Cylinder Performance Test displays bar graphs for each bank’s contribution, use the INSITE™ electronic service tool help file to interpret the results.
  • If the Cylinder Performance Test displays pass or fail for each bank, run the test at least 3 times to verify the results. Read the Test Results under the Results section of the test.

Did the Cylinder Performance Test find an individual failed bank?
YES NO
No Repair No Repair

Guided Step 3E-3 – Measure the resistance between the actuator and the actuator base.

Conditions

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

Action

Measure the resistance between the actuator and the actuator mounting base.
SMALL | MEDIUM | LARGE

Greater than 100k ohms?
YES NO
No Repair

Replace the failed fueling or timing actuator.

Refer to Procedure 019-110 or 019-111.

Repair complete

Guided Step 3E-4 – Swap the front and rear fueling actuators.

Action

Swap the front and rear fueling actuators to determine if the failed bank of cylinders follows the actuator.

  • Refer to Procedure 019-110 for removal and installation.
  • Perform the INSITE™ electronic service tool Cylinder Performance Test.

Does the failed bank follow the metering actuator?
YES NO

Replace the failed fueling actuator. Refer to Procedure 019-110.

 No Repair
Repair complete

Guided Step 3E-5 – Swap the front and rear timing actuators.

Action

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

  • Refer to Procedure 019-111 for removal and installation.
  • Perform the INSITE™ electronic service tool Cylinder Performance Test.

Does the failed bank follow the timing actuator?
YES NO

Replace the failed timing actuator.

Refer to Procedure 019-111.

Troubleshooting procedures need to be repeated from the beginning. A failed injector or actuator should have been detected.
Repair complete

Guided Step 4 – Check the air handling system.

Guided Step 4A – Check the air intake restriction.

Conditions

  • Run the 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.

Refer to Procedure 010-031 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

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

Correct the cause of high intake air restriction.

Check for plugged air filter or restricted air intake piping.

 No Repair
Repair complete

Guided Step 4B – Pressure test the charge air cooler.

Conditions

  • Turn keyswitch OFF.

Action

Pressure test the charge air cooler.

Refer to Procedure 010-027 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Is the pressure drop 5 psi or less in 15 seconds?
YES NO
No Repair

Repair the charge air cooler.

Repair complete

Guided Step 4C – Inspect the charge air cooler.

Conditions

  • Turn keyswitch OFF.

Action

Inspect the charge air cooler for bent or plugged fins.

Bent or plugged fins will force the temperature of the air exiting the cooler to raise and force the engine to work harder to obtain the desired charge flow. A harder working engine will use more fuel.

Is the charge air cooler free from bent or plugged fins?
YES NO
No Repair

Clean the charge air cooler.

Repair complete

Guided Step 4D – Check the exhaust restriction.

Conditions

  • Run engine at advertised horsepower and rpm.

Action

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

Refer to Procedure 011-009 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Is exhaust restriction less than 76 mm Hg [3 in Hg]?
YES NO
No Repair

Repair the exhaust for source of high restriction.

Repair complete

Guided Step 5 – Air handling diagnostic checks.

Guided Step 5A – Start the engine and read the fault codes.

Conditions

  • Connect INSITE™ electronic service tool.
  • Engine running at low idle.

Action

Check the fault codes with the engine running.

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

Are Fault Codes 2355 or 2356 active?
YES NO
No Repair No Repair
Go to appropriate Fault Code troubleshooting tree.

Guided Step 5B – Inspect the turbocharger blades.

Conditions

  • Engine OFF.
  • Remove intake and exhaust connections for turbocharger.

Action

Inspect the compressor and turbine fins for damage or wear.

Measure the turbocharger wheel axial movement.

Check the radial movement of the turbocharger wheel.

Refer to Procedure 010-033 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Was damage found on turbocharger fins or was axial or radial movement out of specification?
YES NO

Replace the turbocharger.

Refer to Procedure 010-033 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

 No Repair
Repair complete

Guided Step 5C – Determination of turbocharger type.

Action

Determine if the turbocharger is a wastegated or variable geometry turbocharger.

Is the turbocharger a variable geometry turbocharger?
YES NO
No Repair No Repair

Guided Step 5D – Check the variable geometry actuator rod for correct travel.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Verify air tanks are fully charged.

Action

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool.

  • Adjust the delay timer in the Turbocharger Actuator Test so rod movement can be observed.
  • Select the Retract Actuator position with INSITE™ electronic service tool.
  • Mark or scribe the VG™ actuator rod at the base of the actuator.
  • Select the Extend Actuator position with INSITE™ electronic service tool.
  • Measure the rod travel by measuring the distance from the base of the turbocharger actuator to the scribe mark.

NOTE: The turbocharger actuator should move quickly and crisply. If the actuator rod movement is slow, there could be a problem with the air supply, a faulty ground connection on the engine or chassis, or mechanical problems with the variable geometry turbocharger assembly.
SMALL | MEDIUM | LARGE

Does the turbocharger actuator rod extend between 10.2 and 11.8 mm [0.402 and 0.465 in]?
YES NO
No Repair No Repair

Guided Step 5D-1 – Check for air leaks and inspect air lines.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Verify vehicle air tanks are fully charged.

Action

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool. Select the Extend Actuator position.

Listen for air leaks at the following components:

  • Turbocharger control valve
  • Turbocharger control shutoff valve inlet connection
  • Turbocharger control shutoff valve outlet connection
  • Turbocharger control valve inlet connection
  • Turbocharger control valve outlet connection
  • Turbocharger actuator
  • All air lines, including the OEM supply line to the turbocharger control shutoff valve, turbocharger control shutoff valve to the turbocharger control valve, and turbocharger control valve to the turbocharger actuator.

Air leaks found in the system?
YES NO

Repair air leaks.

 No Repair
Repair complete

Guided Step 5D-2 – Check the engine and vehicle grounds.

Conditions

  • Turn keyswitch OFF.

Action

Check for loose or corroded engine, chassis, or battery ground connections.

  • Check the engine ground connection.
  • Check the chassis ground connections.
  • Check the battery terminal connections.
SMALL | MEDIUM | LARGE

Are all grounds present, properly grounded, free of corrosion, and tight?
YES NO
No Repair

Replace, clean, or tighten the ground.

Repair complete

Guided Step 5D-3 – Check for air pressure at the turbocharger control valve outlet.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Verify vehicle air tanks are fully charged.

Action

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool. Select the Retract Actuator position.

Remove the air line connection at the outlet of the turbocharger control valve.

Install an M12 Compucheck® fitting, Part Number 3824843, at the outlet of the turbocharger control valve.

Install an air pressure gauge that is capable of reading at least 1034 kPa [150 psi]

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool. Select the Extend Actuator position.

Is vehicle air tank pressure present at the turbocharger control valve outlet?
YES NO
No Repair No Repair

Guided Step 5D-4 – Check for air pressure at the turbocharger control valve outlet.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Verify vehicle air tanks are fully charged.

Action

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool. Select the Retract Actuator position.

Remove the air line connection at the outlet of the turbocharger control valve.

Install an M12 Compucheck® fitting at the outlet of the turbocharger control valve.

Install an air pressure gauge that is capable of reading at least 1034 kPa [150 psi].

Does the pressure gauge read more than 15 psi after 5 minutes?
YES NO

Replace the turbocharger control valve.

Refer to Procedure 019-388.

 No Repair
Repair complete

Guided Step 5D-5 – Check for correct turbocharger actuator travel.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Verify vehicle air tanks are fully charged.

Action

Remove the Variable Geometry Actuator from the turbocharger.

Refer to Procedure 010-113 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

NOTE: Damage to the turbocharger may result if the proper removal procedure is not followed.

Perform the Turbocharger Actuator Test using the INSITE™ electronic service tool. Select the Extend Actuator position.
SMALL | MEDIUM | LARGE

Does the turbocharger actuator rod travel at least 12 mm [0.472 in]?
YES NO

Replace the turbocharger assembly.

Refer to Procedure 010-033 in the Troubleshooting and Repair Manual, Signature, ISX, QSX Engines, Bulletin 3666239.

Replace the turbocharger actuator.

Refer to Procedure 010-113 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.
Repair complete
Repair complete

Guided Step 5D-6 – Check for air pressure at the turbocharger control shutoff valve outlet.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Verify vehicle air tanks are fully charged.
  • Connect INSITE™ electronic service tool.

Action

Use INSITE™ to start the Turbocharger Actuator Test.

Loosen the air line connection at the turbocharger control shutoff valve outlet.
SMALL | MEDIUM | LARGE

Can air be heard escaping from the turbocharger control shutoff valve outlet?
YES NO

Replace the turbocharger control valve.

Refer to Procedure 019-388.

 No Repair
Repair complete

Guided Step 5D-7 – Check for air pressure at the turbocharger control shutoff valve inlet.

Conditions

  • Engine OFF.
  • Turn keyswitch ON.
  • Verify vehicle air tanks are fully charged.

Action

Verify the OEM air supply line is connected to the correct port on the turbocharger control shutoff valve.

Loosen the air line connection at the turbocharger control shutoff inlet.

Can air be heard escaping from the turbocharger control shutoff valve inlet?
YES NO
No Repair

Repair the air supply from the OEM air tanks.

Repair complete

Guided Step 5D-8 – Check for plugged turbocharger control shutoff valve filter.

Conditions

  • Remove the turbocharger control shutoff valve filter.
  • Turn keyswitch ON.
  • Verify vehicle air tanks are fully charged.
  • Connect the INSITE™ electronic service tool.

Action

Use INSITE™ to start the Turbocharger Actuator Test.

Listen for an air leak at the turbocharger control shutoff valve filter head.

Is an air leak present at the turbocharger control shutoff valve filter head?
YES NO

Replace the turbocharger control shutoff valve filter.

Refer to Procedure 010-114 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Replace the turbocharger control shutoff valve.

Refer to Procedure 019-386.
Repair complete
Repair complete

Guided Step 5E – Perform the INSITE™ electronic service tool EGR Valve/Turbocharger Operational Test.

Conditions

  • Turn keyswitch ON.
  • Connect INSITE™ electronic service tool.
  • Engine running at low idle.

Action

Select the EGR/VGT™ Operational Test using the INSITE™ electronic service tool.

NOTE: Prior to running the INSITE™ electronic service tool EGR Valve and EGR Valve/Turbocharger Operational Test, the ECM Calibration Software Phase could possibly need to be updated to the latest Software Phase. The ECM Calibration Phase Software can be checked in INSITE™ electronic service tool, under ‘Features and Parameters’. Expand the selection for ‘System ID and Dataplate’ and go to ‘Calibration Information’. If the Software Phase is earlier than shown below, recalibrate the ECM using the January 2006 INCAL™ CD-ROM, or later. Engines with the Software Phase listed below or later do not require a recalibration.

ISX engines with CM870 (engines built after January 2004) require Software Phase 06050302.

ISX engines with CM870 (engines built before January 2004) require no changes at this time.

This is a warrantable calibration change.

Choose the Turbocharger Actuator option under Test Choices.

Does the Turbocharger Operational Test pass?
YES NO
No Repair No Repair

Guided Step 5E-1 – Check the engine and vehicle grounds.

Conditions

  • Turn keyswitch OFF.

Action

Check for a loose or corroded engine, chassis, or battery ground connection.

  • Check the engine ground connection.
  • Check the chassis ground connections.
  • Check the battery terminal connections.
SMALL | MEDIUM | LARGE

Are all grounds present, properly grounded, free of corrosion, and tight?
YES NO

Replace the variable geometry turbocharger.

Refer to Procedure 010-033 in the Troubleshooting and Repair Manual, Signature, ISX, QSX Engines, Bulletin 3666239.

Replace, clean, or tighten the ground.
Repair complete
Repair complete

Guided Step 5F – Inspect the wastegate actuator hose.

Conditions

  • Engine OFF.
  • Remove the turbocharger if wastegate actuator is inaccessible.

Action

Inspect the integral wastegate actuator hose for cracks or holes.
SMALL | MEDIUM | LARGE

Are holes or cracks found in the wastegate actuator hose?
YES NO

Replace the wastegate actuator hose.

 No Repair
Repair complete

Guided Step 5G – Inspect the wastegate actuator rod for travel.

Conditions

  • Engine OFF.
  • Remove the wastegate actuator hose from the wastegate actuator.

Action

Apply a regulated air supply of 310 kPa [45 psi] to the actuator and check for actuator movement.
SMALL | MEDIUM | LARGE

Does the wastegate actuator rod move?
YES NO
No Repair No Repair

Guided Step 5G-1 – Inspect the wastegate actuator rod for travel.

Conditions

  • Engine OFF.
  • Remove the e-clip from the wastegate pin and disconnect the actuator rod.

Action

Apply a regulated air supply of 310 kPa [45 psi] to the actuator and check for actuator movement.
SMALL | MEDIUM | LARGE

Does the wastegate actuator rod move?
YES NO

Move the wastegate lever on the turbocharger back and forth and check for smooth operation. Replace the turbocharger assembly if the wastegate is seized.

Refer to Procedure 010-033 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Replace the wastegate actuator.

Refer to Procedure 010-050 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.
Repair complete
Repair complete

Guided Step 5H – Measure the resistance of the four-stage wastegate controllers, if equipped.

Conditions

  • Engine OFF.
  • Disconnect the ring terminals from the four-stage wastegate controllers, if equipped.

Action

Measure the resistance from the wastegate controller post to engine block ground.

NOTE: The wastegate controller solenoids must be between 20°C and 26°C [68°F and 78°F] before using the resistance specifications listed.

Are the wastegate controller solenoid resistances between 7.0 and 8.0 ohms?
YES NO
No Repair

Replace the failed wastegate controller.

Refer to Procedure 010-109 in the Troubleshooting and Repair Manual, Signature, ISX, QSX Engines, Bulletin 3666239.

Repair complete

Guided Step 5I – Inspect the four-stage wastegate controller, if equipped.

Conditions

  • Engine OFF.
  • Remove the four-stage wastegate controllers.

Action

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

Damage or debris found on the valve disc, valve seat, or actuator disc?
YES NO

Replace or clean failed components.

 No Repair
Repair complete

Guided Step 6 – Base engine checks.

Guided Step 6A – Verify the overhead adjustments are correct.

Conditions

  • Turn keyswitch OFF.
  • Remove valve cover.

Action

Measure the overhead settings.

Valve Lash Reuse Limits:

  • Intake valve lash: 0.102 mm [0.004 in] to 0.483 mm [0.019 in]
  • Exhaust valve lash: 0.508 mm [0.020 in] to 0.813 mm [0.032 in].

Are the overhead settings within the reuse limits?
YES NO
No Repair

Adjust the overhead settings.

Refer to Procedure 003-004 in the Troubleshooting and Repair Manual, Signature, ISX, QSX Engines, Bulletin 3666239.

Repair complete

Guided Step 6B – Verify the dipstick calibration.

Conditions

  • Turn keyswitch OFF.

Action

Verify the dipstick calibration.

Drain, remove, clean, and install the lubricating oil pan.

Refer to Procedure 007-025 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Check the calibration of the lubricating oil dipstick.

Refer to Procedure 007-009 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Is the dipstick calibrated properly?
YES NO
No Repair

Calibrate the lubricating oil dipstick.

Refer to Procedure 007-009 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Repair complete

Guided Step 6C – Analyze the engine oil.

Conditions

  • Turn keyswitch OFF.

Action

Take an engine oil sample.

Does the engine oil analysis show any signs of wear metals or contaminates?
YES NO
No Repair

Locate and replace the worn component or remove the source of contaminate and repair the engine as necessary.
Repair complete

Guided Step 6D – Check for internal engine damage.

Conditions

  • Turn keyswitch OFF.

Action

Remove the oil filter.

Inspect and replace the oil filter. Refer to Procedure 007-013 in the Troubleshooting and Repair Manual, Signature, ISX, and QSX15 Engines, Bulletin 3666239.

Is any foreign material found in the oil filter?
YES NO

Locate the source of foreign material and repair the engine as necessary.

 No Repair
Repair complete
Return to the troubleshooting steps or contact a local Cummins Authorized Repair Location, if all steps have been completed and checked again.
Last Modified:  09-Jan-2006
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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.