PLUG 3603698 - Caterpillar

Illustration 1 g02105218
Schematic of the "Quick Coupler" switchThis diagnostic code is associated with the "Quick Coupler" switch. This switch has two inputs to the ECM: disengaged wire586-BR and engaged wire 585-YL. During normal operation, one switch input is open and the other input is grounded. If each input is in the same state, the ECM will detect a diagnostic code. This diagnostic code is recorded when voltage is below normal or shorted low.The possible causes of this diagnostic code are listed below:
Short to the ground circuit.
The circuit is shorted.
A failed switch
The ECM may have failed. This is unlikely.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 1529 FMI 04 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:A level 2 warning shall be generated. The quick coupler will not operate until a valid signal for the centered position is seen.Test Step 1. CHECK THE CIRCUIT FOR THE SWITCH.
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the J1 machine harness connector, measure the resistance from contact J1-34 (wire 585-YL) to contact J1-35 (wire 586-BR) with the switch in the Engaged position and the Disengaged position.Expected Result:The measurement of the resistance should be between 5 ohms and 5000 ohms for each switch position.Results:
YES - The resistance is correct for each measurement. Proceed to test step 3.
NO - The measurement of the resistance is greater than 5000 ohms for one or both measurements. The harness or the switch has failed. Proceed to test step 2.Test Step 2. CHECK FOR A SHORT.
Disconnect the switch from the harness.
At the J1 machine harness connector, measure the resistance from contact J1-34 and contact J1-35 to all other J1 contacts.Expected Result:The resistance measurement should be greater than 5000 ohms for each measurement.Results:
OK - The resistance measurement is greater than 5000 ohms for each measurement.Repair: Replace the switch. Proceed to Test Step 3.
NOT OK - The resistance measurement is not greater than 5000 ohms for one or more measurements.Repair: The short is in the circuit with the low resistance measurement. Repair the harness or replace the harness. Verify that the problem has been corrected.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 disconnect switch and the key start switch to the ON position.
Operate the machine.
Check the status of the CID 1529 FMI 04 diagnostic code. Expected Result:The CID 1529 FMI 04 diagnostic code is active. Results:
YES - The CID 1529 FMI 04 diagnostic code 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,