PLATE-ISOLATION 1072884 - Caterpillar

Illustration 1 g01227022
Schematic of the parking brake switch (pull-to-engage)
Illustration 2 g01227024
Schematic of the parking brake switch (push-to-engage)Note: The following test procedure is applicable to the pull-to-engage parking brake switch and the push-to-engage parking brake switch.This diagnostic code is associated with the parking brake switch. The switch is connected to two inputs of the ECM. One contact is open and the other contact is grounded during proper operation.This FMI 03 means that the ECM has determined that the normally open contact and the normally closed contact are open.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0070 FMI 03 is active before performing this procedure.System Response:The parking brake remains engaged when a failure exists for this diagnostic code.Test Step 1. CHECK THE CIRCUIT FOR AN OPEN CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the parking brake switch.
Disconnect the machine harness connector from the ECM.
At the machine harness connector for the switch, place a jumper wire from connector contact 2 to connector contact 6.
At the harness connector for the ECM measure the resistance between connector contact 54 and connector contact 55.Expected Result:The resistance is less than 5 ohms.Results:
YES - The resistance is less than 5 ohms. The harness circuit is correct.