- Diagnostic codes
- The connectors on the Electronic Control Module (ECM)
- Electronic unit injector connector
- Injection actuation pressure
- Fuel supply
- Emergency stop circuit
Note: If the problem only occurs under certain conditions such as high engine speed, full load or engine operating temperature, then perform the test under those operating conditions.
Connect the Caterpillar Electronic Technician (ET) and check for active diagnostic codes or active event codes. Troubleshoot any active diagnostic codes before continuing with this procedure.
Electrical Connections to the ECM
- Check the associated wiring for the following conditions: damage, abrasion and corrosion. Inspect the following connectors: ECM connector, customer connector and engine speed/timing sensor connector. Inspect the input circuit for the keyswitch to the ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.
- Check Cat ET for the CID 168-FMI 02 diagnostic code.
Check the battery connection at the customer connector and the ECM connector. Refer to the electrical schematic. Perform a pull test on the associated wiring. Refer to Troubleshooting, " Electrical Connectors - Inspect".
- The problem may occur when the engine is warmed up. Then as the engine cools, the problem may disappear. The circuit breakers may be exceeding the trip point because of the overheating. Check the circuit breakers. Reset the circuit breakers.
Electronic Unit Injector Connector
Check the unit injector connectors and associated wiring for the following conditions: damage, abrasion, corrosion and incorrect attachment. Refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.
- Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level.
- If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to ensure that the air has been purged from the injection actuation pressure circuit.
- Compare the actual actuation pressure and the desired actuation pressure on Cat ET. If these readings do not agree within 2000 kPa (290 psi), refer to Troubleshooting, "Injection Actuation Pressure - Test".
Check for a problem with the fuel supply and verify the fuel pressure. Verify that the fuel pressure sensor is installed correctly.
Access Cat ET and verify that the status of the emergency stop circuit is off. If the status is on, there may be a problem with the emergency stop circuit.