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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 code is recorded when the ECM detects a short to the +battery from the Implement ECM to the solenoid back to the Implement ECM.
The possible causes for this diagnostic code are listed:
- The signal circuit from the Implement ECM to the solenoid is shorted to the +battery.
- The return circuit from the solenoid is shorted to the +battery.
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.
System Response:
The machine response is listed:
- The implement hydraulic operation is disabled by the machine ECM.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code is corrected.
Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.
Test Step 1. CHECK THE SOLENOID.
- Turn the key start switch to the OFF position.
- Disconnect the solenoid with the diagnostic code from the harness.
- Turn the key start switch to the ON position.
- Place all levers in the HOLD position.
- At the harness connector for the solenoid, measure the voltage from the Implement ECM between contact 1 (wire E918-GN) and contact 2 (wire H708-OR).
Note: This test causes the ECM to log an open circuit diagnostic code for this solenoid. Clear this code from the ECM after troubleshooting.
Expected Result:
The voltage is approximately 2.5 DCV.
Results:
- YES - The voltage is approximately 2.5 DCV.
Repair: The solenoid has failed. Replace the solenoid.
STOP
- NO - The voltage is approximately battery voltage. Proceed to Test Step 2.
Test Step 2. CHECK THE HARNESS.
- Turn the key start switch to the OFF position.
- Disconnect the harness from the Implement ECM.
- Turn the key start switch to the ON position.
- At the harness connector for the Implement ECM, measure the voltage between contact 1 (wire E918-GN) and contact 2 (wire H708-OR).
Expected Result:
The voltage is approximately battery voltage.
Results:
- YES - The voltage is approximately battery voltage.
Repair: There is a short to the +battery in the harness. Repair the harness or replace the harness.
STOP
- NO - The voltage is approximately 0 DCV. The cause or the diagnostic code has not been found. Proceed to Test Step 3.
Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
- Turn the key start switch to the OFF position.
- Inspect all harness connectors and reconnect.
- Turn the key start switch to the ON position.
- Operate the machine.
- Ensure that the diagnostic code is active.
Expected Result:
The diagnostic code is active.
Results:
- YES - The diagnostic code is active.
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".
STOP
- NO - The diagnostic code is NOT active.
Repair: The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.
STOP