CONTROL GP-PARKING BRAKE 3822423 - Caterpillar

Illustration 1 g02079954
Schematic of the L Station Left Conveyor Ratio DialThis diagnostic code is associated with the L Station Left Conveyor Ratio Dial. This diagnostic code is recorded when the LH Operator ECM reads the signal from the conveyor ratio (wire K727-GY) as being shorted to battery(+). The signal (wire K727-GY) connects to contact J1-22 of the ECM.Note: The LH Operator ECM is located under the LH Operator Platform.Possible causes of the diagnostic code are listed below:
The return circuit is open.
The signal circuit is open or the conveyor ratio is disconnected.
The signal circuit is shorted to battery(+).
The conveyor ratio dial has failed.
The ECM has failed. This is unlikely.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, that all the connections are secure and that all the 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:When this diagnostic code is active, the following occurs:
Left conveyor setting will remain at pre-fault setting until propel lever returns to neutral.
When propel lever returns to neutral, conveyor setting will be 50%.
Operator station fault lamp is active.Note: Ensure that CID 0975 FMI 03 is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.Test Step 1. CHECK FOR AN OPEN IN THE RETURN CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
The conveyor ratio dial remains disconnected from the machine harness.
Disconnect the machine harness connector J1 from the ECM.
At the machine harness connector for the conveyor ratio dial, measure the resistance from contact C (wire N701-PK) to ground.Expected Result:The resistance measurement should measure less than 5 ohms.Results:
OK - The resistance measurement is less than 5 ohms. The harness is correct. Proceed to test step 2.
NOT OK - The resistance that is measured is not correct.Repair: There is an open in the machine harness. The open is in the return circuit with the high resistance measurement. Repair the harness or replace the harness.STOPTest Step 2. CHECK FOR AN OPEN IN THE SIGNAL CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 and J2 machine harness connector from the ECM.
At the machine harness connector for the conveyor ratio, install a jumper wire from contact B (wire K727-GY) to contact C (wire N701-PK).
At the machine harness connector J1, measure the resistance from contact J1-22 (wire K727-GY) to Frame Ground.Expected Result:The resistance should measure less than 5 ohms.Results:
OK - The resistance measures less than 5 ohms. Proceed to 3.
NOT OK - The resistance measurement is greater than 5 ohms.Repair: There is an open in the signal circuit. Repair the harness or replace the harness.STOPTest Step 3. CHECK THE SIGNAL CIRCUIT FOR A SHORT.
The disconnect switch