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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 an incomplete electrical path. The electrical path from the Implement ECM to the solenoid back to the Implement ECM is incomplete.
The possible causes for this diagnostic code are listed:
- The signal circuit from the Implement ECM to the solenoids is open.
- The return circuit from the solenoid is open.
- The internal windings for the solenoid have high impedance.
- The internal windings for the solenoid are open.
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, secure and 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.
- Disconnect the solenoid with the diagnostic code from the harness.
- Observe the ON/OFF status of the diagnostic code indicator.
- At the harness connector for the solenoid, place a jumper wire between contact 1 (wire E918-GN) and contact 2 (wire H708-OR).
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 valve 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 THE HARNESS.
- Turn the disconnect switch to the OFF position.
- Remove the jumper wire from contact 1to 2.
- Reconnect the solenoid valve to the harness.
- Disconnect the harness from the Implement ECM.
- At the harness connector for the Implement ECM, measure the resistance between contact 4 (wire H708-OR) and contact 2 (wire E918-GN).
Expected Result:
The resistance is greater than 5000 Ohms (no continuity).
Results:
- YES - The resistance is greater than 5000 Ohms (no continuity).
Repair: The harness circuit has failed. Wire H708-OR is open in the harness between the Implement ECM and the solenoid valve, or the wire E918-GN to the solenoid valve is open. Repair the harness or replace the harness.
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- NO - The resistance is less than 5000 Ohms.
Repair: 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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