850684F 1 Mercury FRONT HANDLE

Illustration 1 g01755713
Schematic
Note: Before performing this test, verify that the brake air pressure is present in the system.Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01141049
J1/P1 ECM connector
Thoroughly inspect the ECM connector J1/P1. Thoroughly inspect the connectors for the brake air pressure switch. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01755714
P1 ECM connector
(P1-45) Brake air pressure switch (NC)
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Position of the Brake Air Pressure Switch on Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector. Start Cat ET.
Turn the keyswitch to the ON position. Start the engine.
Observe the position of the brake air pressure switch on Cat ET. Expected Result:The position of the brake air pressure switch on Cat ET is SWITCH CLOSED.Results:
OK - The position of the brake air pressure switch on Cat ET is correct.Repair: The brake air pressure switch is operating normally. There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The position of the brake air pressure switch on Cat ET is SWITCH OPEN. The circuit for the brake air pressure switch is not operating normally. Proceed to Test Step 3.Test Step 3. Create a Short at the Connector for the LH Brake Air Pressure Switch
Turn the keyswitch to the OFF position.
Disconnect the connector for the LH brake air pressure switch.
Create a short circuit at the connector for the LH brake air pressure switch between terminal 1 and terminal 2.
Turn the keyswitch to the ON position. Start the engine.
Observe the position of the brake air pressure switch on Cat ET.
Turn the keyswitch to the OFF position.
Reconnect the connector for the LH brake air pressure switch. Expected Result:The position of the brake air pressure switch on Cat ET is SWITCH CLOSED.Results:
OK - The position of the brake air pressure switch on Cat ET is correct.Repair: Connect a new LH brake air pressure switch. Verify that the new LH brake air pressure switch solves the problem.STOP
Not OK - The position of the brake air pressure switch on Cat ET is SWITCH OPEN. Verify that wire 201-BK(Black) has continuity between terminal 2 of the connector for the LH brake air pressure switch and engine ground. If wire 201-BK(Black) does not have continuity between the connector and engine ground, repair the wire. If the wire has continuity to engine ground, proceed to Test Step 4.Test Step 4. Create a Short at the Connector for the RH Brake Air Pressure Switch
Turn the keyswitch to the OFF position.
Disconnect the connector for the RH brake air pressure switch.
Create a short circuit at the connector for the RH brake air pressure switch between terminal 1 and terminal 2.
Turn the keyswitch to the ON position. Start the engine.
Observe the position of the brake air pressure switch on Cat ET.
Turn the keyswitch to the OFF position.
Reconnect the connector for the RH brake air pressure switch. Expected Result:The position of the brake air pressure switch on Cat ET is SWITCH CLOSED.Results:
OK - The position of the brake air pressure switch on Cat ET is correct.Repair: Connect a new RH brake air pressure switch. Verify that the new RH brake air pressure switch solves the problem.STOP
Not OK - The position of the brake air pressure switch on Cat ET is SWITCH OPEN. Verify that wire 488-WH(White) has continuity between the connector for the LH brake air pressure switch and the connector for the RH brake air pressure switch. If the wire 488-WH(White) does not have continuity between the two connectors, repair the wire. If the wire has continuity between the two connectors, proceed to Test Step 5.Test Step 5. Create a Short at the ECM
Fabricate a jumper wire that can be used to replace the wire in the ECM connector for the brake air pressure switches. Crimp a connector socket to one end of the jumper wire.
Disconnect the ECM connector J1/P1.
Remove the wire from ECM connector P1-45.
Install the jumper wire into the terminal location for the brake air pressure switch at the ECM connector.
Reconnect the ECM connector J1/P1.
Create a short circuit at the P1 ECM connector between the jumper wire in P1-45 and engine ground.
Turn the keyswitch to the ON position. Start the engine.
Observe the position of the brake air pressure switch on Cat ET.
Turn the keyswitch to the OFF position.
Return all wires to the original configuration. Expected Result:The position of the brake air pressure switch on Cat ET is SWITCH CLOSED.Results:
OK - The position of the brake air pressure switch on Cat ET is correct.Repair: The ECM is operating correctly. The problem is in the harness between the ECM connector and the connector for the RH brake air pressure switch. Repair the harness or the connector.STOP
Not OK - The position of the brake air pressure switch on Cat ET is correct.Repair: Replace the ECM. Refer to Troubleshooting, "ECM - Replace".STOP