Series 60 DDEC V Troubleshooting – Section 3.4 Faulty Electronic Control Unit

Section 3.4
Faulty Electronic Control Unit

To determine if a faulty electronic control module (ECU) is causing the cylinder to misfire, perform the following:‪

Note: Carefully disengage the lock tab on the power harness and injector harness connector when removing.

1. Remove the thru-bolts holding the ECU to the engine; refer to the appropriate service manual, fuel system chapter.
2. Remove the ECU from the engine and tag the ECU for core return.
3. Obtain a new reprogrammed ECU for the engine you are troubleshooting.
4. Inspect the ECU isolators for any damage. Replace if necessary, refer to the appropriate service manual, fuel system chapter.
5. Install the ECU to the engine using thru-bolts; refer to the appropriate service manual, fuel system chapter.
6. Torque the ECU thru-bolts to 23 - 27 N·m (17 - 20 lb·ft).
7. Install the Engine Harness connector and shroud to the ECU. Torque the center screw and two nuts to 5.6 N·m (50 lb·in.).

Section 3.4.1
Faulty ECU Repair

No repair authorized for ECU.‪

Section 3.4.1.1
Verification of Repair for Faulty ECU

Perform the following steps to determine if the new ECU resolved the misfiring cylinder condition:‪

1. Start the engine.
2. Run the engine speed up to the occurrence of the misfiring.
3. Listen for misfiring cylinder.
   1. If the engine is not misfiring, shut down the engine. No further troubleshooting is required.
   2. If the engine is misfiring, shut down the engine and check for worn or damaged valves and cylinder kits; refer to "3.5 Worn or Damaged Valve or Cylinder Kit" .