LINES GP- 3157331 - Caterpillar

Illustration 1 g02594859
Schematic of the Parking Brake Pressure SwitchThis diagnostic code is associated with the Parking Brake Pressure Switch. The switch is connected to two inputs of the ECM. One contact is open and the other contact is grounded during proper operation. Refer to table 1.
Table 1
Status of Parking Brake Pressure Switch    
Parking Brake Pressure Switch    Terminal B
(N/O)
Wire G756-YL
J2-53    Terminal C
(N/C)
C491-PU
J2-52    
Low Pressure
Parking Brake Engaged     Open     Closed    
High Pressure
Parking Brake Engaged     Closed     Open    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 0627 FMI 03 is active before performing this procedure.System Response:The Parking Brake Lockout is 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 connectors from the ECM.
Measure the resistance between contact J1-70 (wire A273-BK) of the machine harness for the ECM and contact A (wire A273-BK) at the switch.Expected Result:The resistance is