HOUSING-BEARING SUPPORT 1V1079 - Caterpillar

Illustration 1 g03012494
Connections of the 8 Volt DC Supply of the Split Drum/Chipspreader ECM
This diagnostic code is recorded when the ECM reads the voltage of the sensor supply circuit as higher than normal.Note: The diagnostic code is transmitted from the Split Drum/Chipspreader ECM to the Machine ECM 1 over the CAN 0 Data Link.Possible causes of this diagnostic code are listed:
The output of sensor supply has shorted to the + battery circuit.
The ECM has failed. This situation is unlikely.Note: 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 in the circuit 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. After making any possible fix to the circuit, cycle the Key Switch in order to determine if the Diagnostic Code still exists. Some Diagnostic Codes may not display until the engine is running.System Response:A Level 2 warning is generated.Test Step 1. CHECK THE VOLTAGE AT A COMPONENT
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from one of the sensors in Illustration 1.
At the harness connector for the sensor, measure the voltage from +V (wire J852-OR(Orange)) to Ground (wire J853-BK(Black)). Expected Result:The voltage measurement is 8.0 1.0 VDC.Results:
OK - The voltage measurement is 8.0 1.0 VDC. The voltage is correct. Proceed to Test Step 4.
NOT OK - The voltage measurement is greater than 8.0 1.0 VDC. The measurement is not correct. Proceed to Test Step 2.Test Step 2. CHECK THE POWER SUPPLY AT THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At the connector for the ECM, use a wire removal tool to remove contact 8 (wire J852-OR(Orange)) and contact 9 (wire J853-BK(Black)). The machine harness connector remains connected to the ECM.
Turn the disconnect switch and the key start switch to the ON position.
Use the multimeter probes in order to make contact on the connector pins. Measure the voltage at the ECM pins between the contact 8 and contact 9. Expected Result:The voltage measurement is 8.0 1.0 VDC.Results:
OK - The voltage measurement is 8.0 1.0 VDC. The voltage is correct. The ECM power supply is correct. Install the wires and sockets that were removed from the ECM harness connector back into the original locations. Proceed to Test Step 3.
NOT OK - The voltage measurement is greater than 8.0 1.0 VDC. The ECM power supply is not correct. The ECM may have failed.Repair: Prior to replacing an ECM, always contact the Technical Communicator for your dealer for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOPTest Step 3. CHECK FOR A