TUBE AS 3560369 - Caterpillar

Illustration 1 g01045123
Schematic of the brake accumulator oil pressure switch for brake application
This diagnostic code is associated with the brake accumulator oil pressure switch for brake application. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) reads the voltage of the switch as being below normal.The possible causes of this diagnostic code are listed:
(Wire X779-GY(Grey)) shorted to frame ground.
The switch has failed.
The ECM has failed.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1612 FMI 04 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:The system indicates that brake accumulator oil pressure is normal.Test Step 1. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
Turn the key start switch and the battery disconnect switch to the OFF position.
Disconnect the switch from the machine harness.
Disconnect the machine harness connectors J1 and J2 from the ECM.
At the machine harness connector J1 and J2, measure the resistance from signal contact J1-38 (wire X779-GY(Grey)) to all possible sources of frame ground. Expected Result:The resistance should be greater than 5 ohms for each measurement.Results:
YES - The resistance is correct. The machine harness is correct. Proceed to Test Step 2.
NO - The resistance is not correct. There is a short in the machine harness.Repair: Repair the harness or replace the harness.STOPTest Step 2. CHECK THE SWITCH
Turn the key start switch and the battery disconnect switch to the ON position.
Access the Service Mode. Place the CID 1612 FMI 04 on hold. Ensure that the diagnostic code is active.
Disconnect the machine harness from the switch. If the switch is not the cause of the diagnostic code, the diagnostic code remains active. If the switch has failed, the diagnostic code is not active. Expected Result:The diagnostic code is active.Results:
OK - The diagnostic code is active. Proceed to Test Step 3.
NOT OK - The diagnostic code is not active. The switch has failed.Repair: Replace the switch.STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS
Inspect the contacts of the harness connectors and clean the harness connectors.
Reconnect all the harness connectors.
Turn the battery disconnect switch and the key start switch to the ON position.
Operate the machine.
Check the status of the CID 1612 FMI 04. Expected Result:The CID 1612 FMI 04 is active. Results:
YES - The CID 1612 FMI 04 is active. The diagnostic code has not been corrected. The ECM may have failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Systems operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for the machine that is being serviced.STOP
NO - The CID 1612 FMI 04 is not active. The diagnostic code does not exist at this time. Repair: The initial diagnostic code was probably caused by