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Electronic Control System Gas Plus Engines – FAULT CODE 462 – B and C Gas Plus

Ignition Control Module Reference Signal Circuit – Shorted Low

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Overview

CODE REASON EFFECT
Fault Code: 462
PID: S66
SPN: 725
FMI: 4
LAMP: Red
SRT: 

Ignition Control Module Reference Signal Circuit – Shorted Low. Low voltage detected at the ECM

Engine will die or
not start

Ignition Reference Signal Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The ignition control module (ICM) is a distributorless ignition module that provides a signal to the coils and delivers high voltage to the spark plugs. The electronic control module (ECM) controls the ICM by providing ignition timing information. The ICM for the C8.3G Plus engine is multispark, disengage-capable during idle conditions to smooth out idle operation

Component Location

The ICM is located next to the ECM on the side of the engine

Shop Talk

The ICM can
not detect whether there is a misfire or a bad spark plug. For the ICM to operate correctly, all connectors
must be clean and tight. Cylinders 3 and 4 are especially critical to the proper operation of the ICM. A poor connection in either of these areas will cause the engine
not to start

Cautions and Warnings

 WARNING 

EXTREMELY HIGH VOLTAGE. Do not touch any ignition wiring or component while the engine is operating unless an insulated tool is being used to prevent electrical shock and damage to the equipment
 CAUTION 

To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM
 CAUTION 

To reduce the possibility of pin and harness damage, use the following test leads when taking a measurement:
Part Number 3822758 – male Deutsch™/AMP™/Metri-Pack™ test lead
Part Number 3823995 – male Weather Pack™ test lead

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Read the fault codes. Fault Code 462 active?
STEP 2. Check the ignition control module.  
  STEP 2A. Check the system voltage. Less than 12-VDC?
  STEP 2B. Check the ICM supply voltage. Less than 12-VDC?
  STEP 2C. Inspect the ICM and engine harness connector pins. Dirty or damaged pins?
  STEP 2D. Check the ICM supply voltage. Less than 12-VDC?
  STEP 2E. Check for a damaged ICM 15 ampere fuse. Less than 10 ohms?
  STEP 2F. Read the fault codes. Fault Code 462 active?
STEP 3. Check the engine harness.  
  STEP 3A. Inspect the engine harness and the ECM connector pins. Dirty or damaged pins?
  STEP 3B. Check for an open circuit. Less than 10 ohms?
  STEP 3C. Check for a short circuit to ground. More than 100k ohms?
  STEP 3D. Check for a short circuit from pin to pin. More than 100k ohms?
  STEP 3E. Check the ECM for active fault codes. Fault Code 462 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 462 inactive?
  STEP 5B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Read the fault codes.

Conditions

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

Action

Read the fault codes.

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

Fault Code 462 active?
YES NO
No Repair No Repair

Use the following procedure for troubleshooting an inactive or intermittent fault code.
019-362 in Section 19.

Guided Step 2 – Check the ignition control module (ICM).

Guided Step 2A – Check the system voltage.

Conditions

  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool

Action

Check the system voltage.

  • Use INSITE™ electronic service tool to read the Battery Voltage parameter

Less than 12-VDC?
YES NO

Recharge or replace the vehicle battery.
013-007 in Section 13.

No Repair

Guided Step 2B – Check the ICM supply voltage.

Conditions

  • Turn keyswitch ON
  • Disconnect engine harness from the ICM connector

Action

Check the Switched Battery (+) voltage.

  • Measure the voltage at pin A at the ICM connector

Refer to the circuit diagram or wiring diagram for component pin identification

Less than 12-VDC?
YES NO
No Repair No Repair

Guided Step 2C – Inspect the ICM and engine harness connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness from the ICM and the 31-pin OEM connector

Action

Inspect the module, engine harness, and OEM connector pins for the following:

  • Loose connector
  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Moisture in or on the connector
  • Missing or damaged connector seals
  • Dirt or debris in or on the connector pins
  • Connector shell broken
  • Wire insulation damage
  • Damaged connector locking tab

Use the following procedure for general inspection techniques.
019-361 in Section 19.

Dirty or damaged pins?
YES NO

Repair the damaged pins. Repair or replace the engine harness, or replace the ICM, whichever has the damaged pins

  • Flush the dirt, debris, or moisture from the connector pins. Use electronic contact cleaner, Part Number 3824510
  • Install the appropriate connector seal if it is damaged or missing
  • Repair the engine harness.
    019-201 in Section 19.
  • Replace the engine harness. Refer to Procedure
    019-043 in Section 19.
  • Replace the sensor. Refer to Procedure
    019-105 in Section 19.
No Repair

Guided Step 2D – Check the ICM supply voltage.

Conditions

  • Turn keyswitch ON
  • Disconnect the engine harness from the 31-pin OEM connector

Action

Check the Switched Battery (+) voltage.

  • Measure the voltage at pins 27 and 30 at the OEM connector

Refer to the circuit diagram or wiring diagram for component pin identification

Less than 12-VDC?
YES NO
No Repair No Repair

Guided Step 2E – Check for a damaged ICM 15 ampere fuse.

Conditions

  • Turn keyswitch OFF
  • Remove the 15 ampere ICM fuse

Action

Check for a damaged fuse.

  • Remove the 15 ampere ICM fuse
  • Use a multimeter to test the continuity of the fuse

Refer to the circuit diagram or wiring diagram for component pin identification

Use the following procedure for general resistance measurement techniques.
019-360 in Section 19.

Less than 10 ohms?
YES NO
No Repair

A damaged fuse has been detected. Replace the fuse

Guided Step 2F – Read the fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool

Action

Read the fault codes.

  • Start the engine and let it idle for 1 minute
  • Use INSITE™ electronic service tool to read the fault codes

Fault Code 462 active?
YES NO
No Repair No Repair

Guided Step 3 – Check the engine harness.

Guided Step 3A – Inspect the engine harness and the ECM connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness connector 1 and connector 2 from the ECM
  • Disconnect the engine harness from the OEM harness at the 23-pin and 31-pin OEM connectors

Action

Inspect the engine harness, OEM 23-pin, OEM 31-pin, and ECM connector pins for the following:

  • Loose connector
  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Moisture in or on the connector
  • Missing or damaged connector seals
  • Dirt or debris in or on the connector pins
  • Connector shell broken
  • Wire insulation damage
  • Damaged connector locking tab

Use the following procedure for general inspection techniques.
019-361 in Section 19.

Dirty or damaged pins?
YES NO

Repair the damaged pins. Repair or replace the engine harness, or replace the ECM, whichever has the damaged pins

  • Flush the dirt, debris, or moisture from the connector pins. Use electronic contact cleaner, Part Number 3824510
  • Install the appropriate connector seal if it is damaged or missing
  • Repair the engine harness.
    019-204 in Section 19.
  • Replace the engine harness.
    019-043 in Section 19.
  • Call for authorization to replace the ECM. Upon receipt of authorization, replace the ECM.
    019-031 in Section 19.
No Repair

Guided Step 3B – Check for an open circuit.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness from the ICM
  • Disconnect the engine harness connector 1 from the ECM

Action

Check for an open circuit.

  • Measure the resistance between the ICM SIGNAL reference pin in the engine harness ECM connector to the ICM SIGNAL reference pin in the engine harness ICM connector

Refer to the circuit diagram or wiring diagram for component pin identification

Use the following procedure for general resistance measurement techniques.
019-360 in Section 19.

SMALL | MEDIUM | LARGE

Less than 10 ohms?
YES NO
No Repair

Repair or replace the engine harness

Guided Step 3C – Check for a short circuit to ground.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness from the ICM
  • Disconnect the engine harness from the OEM harness at the 23-pin and 31-pin OEM connectors
  • Disconnect engine harness connector 1 from the ECM

Action

Check for a short circuit to ground.

  • Measure the resistance between the ICM SIGNAL reference pin in engine harness ECM connector 1 to engine block ground

Refer to the circuit diagram or wiring diagram for component pin identification

Use the following procedure for general resistance measurement techniques.
019-360 in Section 19.

SMALL | MEDIUM | LARGE

More than 100k ohms?
YES NO
No Repair

Repair or replace the engine harness

  • Flush the dirt, debris, or moisture from the connector pins. Use electronic contact cleaner, Part Number 3824510
  • Install the appropriate connector seal if it is damaged or missing
  • Repair the engine harness.
    019-204 in Section 19.
  • Replace the engine harness.
    019-043 in Section 19.

Guided Step 3D – Check for a short circuit from pin to pin.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness from the ICM
  • Disconnect the engine harness from the OEM harness at the 23-pin and 31-pin OEM connectors
  • Disconnect engine harness connector 1 and connector 2 from the ECM

Action

Check for a short circuit from pin to pin.

  • Measure the resistance between the ICM SIGNAL reference pin in engine harness ECM connector 1 to all other pins in the connector
  • Measure the resistance between the ICM SIGNAL reference pin in engine harness ECM connector 1 to all other pins in engine harness ECM connector 2

Refer to the circuit diagram or wiring diagram for component pin identification

Use the following procedure for general resistance measurement techniques.
019-360 in Section 19.

SMALL | MEDIUM | LARGE

Greater than 100k ohms?
YES NO
No Repair

Repair or replace the engine harness

  • Flush the dirt, debris, or moisture from the connector pins. Use electronic contact cleaner, Part Number 3824510
  • Install the appropriate connector seal if it is damaged or missing
  • Repair the engine harness.
    019-204 in Section 19.
  • Replace the engine harness.
    019-043 in Section 19.

Guided Step 3E – Check the ECM for active fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect the INSITE™ electronic service tool

Action

Read the fault codes.

  • Start the engine and let it idle for 1 minute
  • Use INSITE™ electronic service tool to read the fault codes

Fault Code 462 inactive?
YES NO
No Repair

Replace the ICM.
019-105 in Section 19.

Guided Step 4 – Clear the fault codes.

Guided Step 4A – Disable the fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool

Action

Disable the fault code.

  • Turn keyswitch OFF and wait 5 seconds
  • Start the engine and let it idle for 1 minute
  • Use INSITE™ electronic service tool to verify that Fault Code 462 is inactive

Fault Code 462 inactive?
YES NO
No Repair

Return to the troubleshooting steps or contact a Cummins® Authorized Repair Location if all steps have been completed and checked again

Guided Step 4B – Clear the inactive fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool

Action

Clear the inactive fault codes.

  • Use INSITE™ electronic service tool to erase the inactive fault codes

All fault codes cleared?
YES NO
No Repair

Troubleshoot any remaining active fault codes
Repair complete
Appropriate troubleshooting charts
Last Modified:  22-Apr-2010
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