CARRIER 1T0545 - Caterpillar

Illustration 1 g01081218
Schematic of the Manual Select switchThis diagnostic code is associated with the manual select switch. The switch is connected to two inputs of the ECM. The inputs are normally open and normally closed. One of the inputs is open and the other input is grounded during proper operation.The FMI 04 means that the ECM has determined that the circuits are grounded.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected.Ensure that the diagnostic code of CID 875 FMI 04 is active before performing this procedure.System Response:When this diagnostic code is active the hydraulic control system will default to the "Auto Not Allowed" state.Test Step 1. CHECK THE SWITCH
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the switch.
Turn the key start switch and the disconnect switch to the ON position.Expected Result:The CID 875 FMI 04 has been replaced by CID 875 FMI 03.Results:
OK - The CID 875 FMI 04 has been replaced by CID 875 FMI 03. The machine harness and the ECM are correct. Proceed to Test Step 3.
NOT OK - The CID 875 FMI 04 is still active. Proceed to Test Step 2.Test Step 2. CHECK THE HARNESS
Turn the disconnect switch and the key start switch to the OFF position.
The machine harness remains disconnected from the switch.
Disconnect the machine harness connector(s) from the ECMand the switch.
Measure the resistance between contacts"J1-34" (wire Y931-BR) and "J1-35" (wire Y932-GY) of the machine harness to all the contacts that are used in machine harness connectors for the ECM. Note the resistance.Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
YES - Each resistance measurement is greater than 5000 ohms. The ECM has 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. See Troubleshooting, "Module - Replace".STOP
NO - One or more of the resistance measurements are less than 5 ohms. The harness has failed. The short is between "J1-34" (wire Y931-BR) and the circuit with the lowest resistance or the short is between "J1-35" (wire Y932-GY) and the circuit with the lowest resistance.Repair: Repair the wiring harness or replace the wiring harness.STOPTest Step 3. CHECK THE OPERATION OF THE SWITCH.
The machine harness remains disconnected from the switch.
Connect one lead from a multimeter to contact "5" (wire J766-BR) of the harness connector for the switch.
Connect the other lead from a multimeter to contact "8" (wire Y931-BR) of the harness connector for the switch.
Measure the resistance between contact "5" (wire J766-BR) and contact "8" (wire Y931-BR). Note the resistance.
Disconnect the lead from contact "8" (wire Y931-BR) and connect the lead to contact "9" (wire Y932-GY).
Measure the resistance between contact "5" (wire J766-BR) and contact "9" (wire Y932-GY).Expected Result:The resistance from contact "5" to contact "9" is less than 5 ohms, and the resistance from contact "5" to