COIL AS 8C5575 - Caterpillar

Illustration 1 g02763356
Schematic of the 587T and 572RII Parking Brake Switch
Illustration 2 g02765516
Schematic of the PL83, 583T, and PL87 Parking Brake SwitchThis switch has two inputs to the ECM. The two inputs are normally open and normally closed. During normal operation, one of the inputs is open. The other input is grounded. When a circuit is measured with a voltmeter, an open circuit will measure approximately 5 VDC and a closed circuit will measure approximately 0 VDC. An FMI 03 diagnostic code is recorded when the status of both the inputs are open.The possible causes of this diagnostic code are listed below:
The return circuit (wire 202-BK) is open.
The "NORMALLY OPEN" signal circuit (wire 419-YL) is open.
The "NORMALLY CLOSED" signal circuit (wire F780-PK) is open.
The "NORMALLY OPEN" signal circuit (wire 419-YL) is shorted to the + battery.
The "NORMALLY CLOSED" signal circuit (wire F780-PK) is shorted to the + battery.
The parking brake switch has failed.
The ECM has failed. An ECM failure is unlikely. Test Step 1. CHECK THE GROUND CIRCUIT AT THE SWITCH
Turn the key start switch to the OFF position.
Measure the resistance between contact "COMMON" (wire 202-BK) at the switch and frame ground.Expected Result:The resistance should be less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5 ohms. Proceed to Test Step 2.Test Step 2. CHECK THE GROUND CIRCUIT FOR AN OPEN
Disconnect the machine harness connectors from the ECM.
Measure the resistance between contact J1-57 (wire 202-BK) and contact "COMMON" (wire 202-BK) at the switch.Expected Result:The resistance should be less than 5 ohms.Results:
OK - The resistance is less than 5 ohms.Repair: An ECM failure is unlikely. Exit this procedure and perform this procedure again. If the diagnostic code is still present, replace the ECM. Refer to Troubleshooting, "Electronic Control Module (ECM) - Replace"STOP
NOT OK - The resistance is greater than 5 ohms.Repair: The return circuit (wire 202-BK) is open in the machine harness. Repair the machine harness or replace the machine harnessSTOPTest Step 3. CHECK THE SWITCH IN THE OFF POSITION
Place the switch in the OFF position.
Measure the resistance between contact "COMMON"