REDUCER 4533735 - Caterpillar

Illustration 1 g00840403
Schematic of the Switch (service brake pedal)This diagnostic code is associated with the Switch (service brake pedal). The switch is connected to two inputs of the machine ECM. One contact is open and the other contact is grounded during proper operation. The possible causes of this diagnostic code are listed:
The normally open contact and the normally closed contact are open.
The contact that is currently closed to ground is shorted to the +battery circuit.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 0298 FMI 05 is active before performing this procedure.System Response:When this diagnostic code is active, the machine ECM will be unable to determine the state of the switch. The parking brake will be engaged if there is no request for travel. The brake lights will shut off. The oscillating axle will be locked. The pilot hydraulics for the travel function will be disabled.Test Step 1. CHECK THE GROUND CIRCUIT OF THE SWITCH IN THE HARNESS.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector(s) from the machine ECM.
Measure the resistance between contact J1-9 (wire A235-BK) of the machine harness for the machine ECM and contact A (wire A235-BK) at the switch.Expected Result:The resistance is less than 5 ohms. Results:
OK - The resistance is less than 5 ohms. The circuit is correct. Proceed to Test Step 2.
NOT OK - The resistance is greater than 5000 ohms. The circuit is open. The machine harness has failed.Repair: Repair the machine harness or replace the machine harness. Stop.Test Step 2. CHECK THE SWITCH CIRCUITS FOR A SHORT TO THE +BATTERY CIRCUIT.
The machine harness connector(s) remains disconnected from the machine ECM.
The disconnect switch and the key start switch remain in the OFF position.
Disconnect contact C (wire F790-BR) and contact B (wire F787-GN) from the connector of the switch.
At the machine harness connector for