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| Illustration 1 | g02623458 |
Schematic for the Pilot Pressure Solenoid Valve | |
This solenoid is connected to the implement ECM. The Implement ECM sends the diagnostic information to the Machine ECM via the CAN data link. This diagnostic code is recorded when the Implement ECM detects a short to ground from the Implement ECM to the solenoid.
The possible causes for this diagnostic code are listed:
- The internal windings for the solenoid have low impedance.
- The internal windings for the solenoid are shorted.
- The signal circuit from the implement ECM to the solenoid is shorted to ground.
Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean and secure. Verify that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.
Test Step 1. CHECK THE SOLENOID.
- Turn the disconnect switch and the key start switch to the ON position.
- Observe the status of the diagnostic code.
- Disconnect the solenoid with the diagnostic code from the harness.
Expected Result:
The diagnostic code remains active.
Results:
- YES - The diagnostic code remains active. The harness has failed or the Implement ECM has failed. Proceed to Test Step 2.
- NO - The diagnostic code is inactive.
Repair: The solenoid has failed or the connecting harness has failed. Repeat this test in order to verify the failure. Repair the solenoid or replace the solenoid. Repair the connecting harness or replace the connecting harness at the solenoid.
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Test Step 2. CHECK FOR A SHORTED HARNESS.
- Turn the disconnect switch to the OFF position.
- The solenoid valve from the previous test step remains disconnected.
- Disconnect the harness from the Implement ECM.
- At the harness connector for the ECM, measure the resistance between contact for the failed solenoid circuit 2 (wire E918-GN) and chassis ground.
Expected Result:
The resistance is less than 5000 Ohms.
Results:
- YES - The resistance is less than 5000 Ohms.
Repair: The harness has failed. The corresponding solenoid wire is shorted to ground in the harness. Repair the harness or replace the harness.
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- NO - Resistance is greater than 5000 Ohms (no continuity).
Repair: The harness circuit resistance is correct. Check the circuit again.If the cause of the problem is not found, contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the Implement ECM requires replacement, see Troubleshooting, "Electronic Control Module (ECM) - Replace".
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