LINES GP- 3138529 - Caterpillar

Illustration 1 g02033559
Schematic of the parking brake switchThe parking brake switches have two inputs to the Computerized Profiler Control ECM. During normal operation, only one switch input is grounded. The preceding chart shows the continuity of each switch circuit for the two positions of the switch. When a circuit is measured with a voltmeter, an open circuit will measure 5 DCV and a returned circuit will measure approximately 0 DCV. A failure is detected when both the inputs are open or grounded.An FMI F02 fault is recorded when both the inputs are open or returned.The possible causes of this diagnostic code are listed below:
The return circuit (wire 229-BK) is open.
The signal circuit (wire C744-PU) is open.
The signal circuit (wire C701-YL) is open.
The signal circuit (wire C744-PU) is grounded.
The signal circuit (wire C701-YL) is grounded.
The parking brake switch is faulty.
The ECM has failed. This is unlikely.System Response:The machine response is listed below:
A Category 2 warning is shown on the monitor.
Propulsion is disabled or no propulsion is allowed until the fault is no longer present.Note: Ensure that the CID 070 FMI F02 is active and that the fault is present. If the fault present indicator is not ON, toggle the switch to the position until the fault present indicator is ON.Test Step 1. CHECK THE SIGNAL CIRCUIT (C701-YL) FOR PROPER OPERATIONThis step checks the continuity of wire (C701-YL) in the machine harness and through the parking brake switches.
Turn the key start switch to the OFF position.
Disconnect the machine harness from the ECM.
At the machine harness connector, check continuity from contact 12 (wire C701-YL) to return contact 39 (wire 229-BK).Expected Result:With the parking brake switches in the PARK position, there should be continuity. If the parking brake switches are not in the PARK position, there should be no continuity.Results:
OK - With the parking brake switches in the PARK position, there is continuity. If the parking brake switches are not in the PARK position, there is no continuity. Proceed to Test Step 3.
NOT OK - With the parking brake switches in the PARK position, there is no continuity. If the parking brake switches are not in the PARK position, there is continuity. The switch or the machine harness is faulty. Proceed to Test Step 2.Test Step 2. CHECK THE CIRCUITS OF EACH SWITCHESThis check determines whether the switch or the machine harness is faulty.
At each of the parking brake switch, disconnect the wire (229-BK) in the terminal 3 and the wire (C701-YL) in the terminal 4.
At each of the parking brake switch, check the continuity between the wire (C701-YL) in the terminal 4 and the wire (229-BK) in the terminal 3.Expected Result:With the parking brake switch in the PARK position, there should be continuity. If the parking brake switches are not in the PARK position, there is no continuity.Results:
OK - With the parking brake switch in the PARK position, there should be continuity. If the parking brake switches are not in the PARK position, there is no continuity. The machine harness is faulty.