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FAULT CODE 321 M11/L10

Injector Circuit – Number 4

Overview

CODE REASON EFFECT
Fault Code: 321 M11
PID: S004
SPN: 737
FMI: 6
LAMP: Yellow
SRT: 00-604

Current detected at number 4 injector return pin 6 of the actuator harness when the voltage supply at pin 15 of the actuator harness connector is off.

Engine speed derate to 1400 to 1600 rpm. Current to injector is shut off.

Injector Circuit – Number 4
SMALL | MEDIUM | LARGE

Circuit Description

The injector solenoid valves are actuated by the electronic control module (ECM) to control fuel metering and timing. Each injector solenoid is connected to the ECM by a supply wire and a return wire. An electrical pulse is sent to the injector from the ECM on the supply wire and returns to the ECM on the return wire after actuating the solenoid. Each solenoid valve is normally open, and it is only closed by an electrical pulse from the ECM during fuel injection and metering.

Component Location

There are two pieces to an M11 actuator harness – one internal and the other external. The external portion of the actuator harness extends from the C connector port in the ECM to the backside of the rocker lever housing. The external harness connects to the internal harness at a 12-pin connector. The internal actuator harness runs along the inside of the rocker lever housing on the right side. It has six connectors spaced along its length – one for each injector solenoid. These connectors attach to the pigtail connector on each injector.

Cautions and Warnings

 WARNING 

The injector solenoids receive high voltage when the engine is operating. To reduce the possibility of personal injury from electrical shock, do not wear jewelry or damp clothing, and do not touch the injector solenoids or the solenoid wires when the engine is operating.
 CAUTION 

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

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

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the internal actuator harness.  
  STEP 1A. Inspect the internal and external actuator harness pass-through connector pins. No damaged pins
  STEP 1B. Read the fault codes. Fault Code 321 active
  STEP 1C. Check for a short circuit from pin to pin. More than 100k ohms
STEP 2. Check the external actuator harness.  
  STEP 2A. Inspect the actuator harness and the ECM connector pins. No damaged pins
  STEP 2B. Read the fault codes. Fault Code 321 active
  STEP 2C. Check for a short circuit from pin to pin. More than 100k ohms
STEP 3. Check the ECM.  
  STEP 3A. Check the ECM response. Fault Code 321 inactive
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 321 inactive
  STEP 4B. Clear the inactive fault codes. All fault codes cleared

Guided Step 1 – Check the internal actuator harness.

 WARNING 

The injector solenoids receive high voltage when the engine is operating. To reduce the possibility of personal injury from electrical shock, do not wear jewelry or damp clothing, and do not touch the injector solenoids or the solenoid wires when the engine is operating.
Guided Step 1A – Inspect the internal and external actuator harness pass-through connector pins.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the external actuator harness from the 12-pin connector.
  • Disconnect the internal actuator harness from the 12-pin connector.

Action

  • Bent or broken pins
  • Pushed back or expanded pins
  • Corroded pins
  • Moisture in or on the connector
  • Missing or damaged seals.
OK NOT OK

No damaged pins

Repair the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Replace the internal actuator harness. Refer to Procedure 019-043.
  • Replace the actuator harness. Refer to Procedure 019-043.

Guided Step 1B – Read the fault codes.

Conditions

  • Turn keyswitch OFF.
  • Connect all components.

Action

  • Read the active fault codes using INSITE™.
OK NOT OK

Fault Code 321 active

Repair complete.

 WARNING 

The injector solenoids receive high voltage when the engine is operating. To reduce the possibility of personal injury from electrical shock, do not wear jewelry or damp clothing, and do not touch the injector solenoids or the solenoid wires when the engine is operating.
 CAUTION 

To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement:
Part Number 3822758 – male Deutsch/AMP/Metri-Pack test lead.
Guided Step 1C – Check for a short circuit from pin to pin.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the internal actuator harness 12-pin connector.

Action

  • Measure the resistance from pin L of the 12-pin connector to all other pins in the connector, except pin M.
  • Measure the resistance from pin M of the 12-pin connector to all other pins in the connector, except pin L.
SMALL | MEDIUM | LARGE
OK NOT OK

More than 100k ohms

Replace the internal actuator harness. Refer to Procedure 019-043.

Guided Step 2 – Check the external actuator harness.

 WARNING 

The injector solenoids receive high voltage when the engine is operating. To reduce the possibility of personal injury from electrical shock, do not wear jewelry or damp clothing, and do not touch the injector solenoids or the solenoid wires when the engine is operating.
 CAUTION 

To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM.
Guided Step 2A – Inspect the actuator harness and the ECM connector pins.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the actuator harness connector from the ECM.

Action

  • Bent or broken pins
  • Pushed back or expanded pins
  • Corroded pins
  • Moisture in or on the connector
  • Missing or damaged seals.
OK NOT OK

No damaged pins

Repair the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Repair the actuator harness. Refer to Procedure 019-203.
  • Replace the actuator harness. Refer to Procedure 019-043.
  • Replace the ECM. Refer to Procedure 019-031.
  • Replace the o-ring on the 28-pin connector if it is damaged or missing. Refer to Procedure 019-203.

Guided Step 2B – Read the fault codes.

Conditions

  • Turn keyswitch OFF.
  • Connect all components.

Action

  • Read the active fault codes using INSITE™.
OK NOT OK

Fault Code 321 active

Repair complete.

 WARNING 

The injector solenoids receive high voltage when the engine is operating. To reduce the possibility of personal injury from electrical shock, do not wear jewelry or damp clothing, and do not touch the injector solenoids or the solenoid wires when the engine is operating.
 CAUTION 

To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement:
Part Number 3822758 – male Deutsch/AMP/Metri-Pack test lead.
Guided Step 2C – Check for a short circuit from pin to pin.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the actuator harness connector from the ECM.
  • Disconnect the external actuator harness from the 12-pin connector.

Action

  • Measure the resistance from pin 15 in the actuator harness connector to all other pins in the connector.
  • Measure the resistance from pin 6 in the actuator harness connector to all other pins in the connector.
SMALL | MEDIUM | LARGE
OK NOT OK

More than 100k ohms

Replace the actuator harness. Refer to Procedure 019-043.

Guided Step 3 – Check the ECM.

 CAUTION 

To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM.
Guided Step 3A – Check the ECM response.

Conditions

  • Turn keyswitch OFF.
  • Disconnect pins 6 and 15 of the actuator harness connector from the ECM.

Action

  • Start the engine and let it idle for 1 minute.
  • Read the active fault codes using INSITE™.
OK NOT OK

Fault Code 321 inactive

Replace the ECM. Refer to Procedure 019-031.

Guided Step 4 – Clear the fault codes.

Guided Step 4A – Disable the fault code.

Conditions

  • Connect all the components.

Action

  • Start the engine and let it idle for 1 minute.
  • Verify that Fault Code 321 is inactive.
OK NOT OK

Fault Code 321 inactive

Return to the troubleshooting steps or contact your nearest Cummins Authorized Repair Location if all the steps have been completed and checked again.

Guided Step 4B – Clear the inactive fault codes.

Conditions

  • Connect all of the components.

Action

  • Erase the inactive fault codes using INSITE™.
OK NOT OK

All fault codes cleared

Troubleshoot any remaining active fault codes.
Repair complete
Appropriate troubleshooting chart
Last Modified:  10-Nov-2003
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Published by Jack

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