The Engine Control Module (ECM) monitors the current flow through the coils of the applicable components
The ECM sets a diagnostic trouble code if the current flow through a coil is incorrect. These codes can be activated only when the ECM is sending a command to the control valves. A -5 code indicates that the current flow through the circuit is low and there is an open in the circuit. A -6 code indicates that the current flow through the circuit is high and there is a short in the circuit.
Table 1 lists the diagnostic codes for incorrect current flow.
Note: Some of the following codes may not be applicable for certain applications.
| Diagnostic Trouble Codes | |||
|---|---|---|---|
| CDL Code | J1939 Code | Code Description | Comments |
| 1922-5 | 2949-5 | Engine Intake Valve Actuation System Oil Pressure Control Valve : Current Below Normal | This code indicates that there is a problem with the Engine Intake Valve Actuation System Oil Pressure Control Valve circuit or solenoid. |
| 1922-6 | 2949-6 | Engine Intake Valve Actuation System Oil Pressure Control Valve : Current Above Normal | This code indicates that there is a problem with the Engine Intake Valve Actuation System Oil Pressure Control Valve circuit or solenoid. |
| Follow the troubleshooting procedure in order to identify the root cause of the problem. | |||
Note: Refer to Troubleshooting, "Component Location" in this manual for the proper location of the components listed in this procedure.
Electrical Checkouts on the Caterpillar Electronic Technician (ET)
| Component | Electrical Checkout |
| Engine retarder solenoid | Engine Retarder Solenoid Override - initiate an engine retarder solenoid override through Cat ET in order to activate the engine retarder solenoid. Review active diagnostic codes to determine what code is present. |
| |
| Illustration 1 | g03576457 |
Test Step 1. Determine the Diagnostic Code
- Establish communication between Cat ET and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
- Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
Wait at least 30 seconds in order for the diagnostic codes to become active.
- Look for these active codes or logged codes:
- -5
- -6
Results:
- A -5 diagnostic code is active. - Proceed to Test Step 2.
- A -6 diagnostic code is active. - Proceed to Test Step 3.
Test Step 2. Check the Wiring for an Open Circuit
- Verify that the harness connector is free of debris, free of corrosion and securely connected.
- Disconnect the solenoid from the engine harness.
- Connect a jumper wire between the terminals of the harness connector for the suspect coil. The coil is replaced with a short circuit.
- Clear the -5 code.
- Perform the appropriate electrical checkout. Refer to Table 2.
Results:
- A -5 code became active during the electrical checkout. - The ECM did not detect the jumper wire. There is an open circuit in the wiring between the coil and the ECM connector. There may be a problem with a connector.
Repair: Repair the appropriate harness wiring or replace the appropriate harness.
Verify that the problem is resolved.
STOP
- A -6 code is activated during the electrical checkout. The ECM detected the jumper wire. There is a problem with the solenoid. Clear the -6 code by cycling the keyswitch to the Off position. -
Repair: Replace the solenoid.
Verify that the problem is resolved.
STOP
Test Step 3. Check the Wiring for a Short Circuit
- Disconnect the solenoid from the engine harness.
- Clear the -6 code by cycling the keyswitch to the Off position.
- Perform the appropriate electrical checkout. Refer to Table 2.
Results:
- A -6 code became active during the electrical checkout. - The ECM did not detect the open circuit. There is a short circuit in the wiring between the coil and the ECM connector. There may be a problem with a connector.
Repair: Repair the appropriate harness wiring or replace the appropriate harness.
Verify that the problem is resolved.
STOP
- A -5 code became active during the electrical checkout. - The ECM detected the open circuit. The wiring is OK. The coil has a short circuit.
Repair: Replace the solenoid.
Verify that the problem is resolved.
STOP