F286192 Force THROTTLE CAM

Illustration 1 g01141226
Schematic for throttle lock switch
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01144470
Left side engine view
(1) J1/P1 ECM connectors
Illustration 3 g01144471
Control console next to operator's seat (right side)
(2) Throttle lock switch
Thoroughly inspect ECM connector (1) and the connector for switch (2). Also inspect each of the machine connectors that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 4 g01141263
P1 ECM connector
(P1-5) Digital sensor return
(P1-44) Throttle lock control (N/O)
(P1-45) Throttle lock control (N/C)
Illustration 5 g01141445
J705 Throttle lock switch connector
(J705-3) Throttle lock control (N/C)
(J705-4) Digital sensor return
(J705-5) Throttle lock control (N/O)
Perform a 45 N (10 lb) pull test on all of the wires that are in the ECM connectors and on wires (3), (4), and (5) of the connector for the throttle lock switch.
Check the torque of the allen head screw on the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the switch back to the ECM. Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be in good repair. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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 for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Check the "Active Diagnostic Codes" screen for a 549-02 diagnostic code. Toggle the throttle lock switch and hold the switch in the active position for several seconds. Check Cat ET for the active diagnostic code.
Turn the keyswitch to the OFF position. Expected Result:A 549-02 diagnostic code is not active.Results:
OK - The switch is operating normally. There may be an intermittent problem.Repair: Check the wiring harness and service equipment for an intermittent electrical problem. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A 549-02 diagnostic code is active. Proceed to Test Step 3.Test Step 3. Check the Resistance of the Switch Circuit at the ECM Connector
Ensure that the keyswitch is in the OFF position.
Disconnect the P1 connector. Note: Wiggle the harnesses during the following measurements in order to detect an intermittent problem.
Measure the resistance between terminals P1-5 (digital sensor return) and P1-44 (throttle lock control (N/O)). The correct resistance measurement is an open circuit.
Measure the resistance between terminals P1-5 (digital sensor return) and P1-45 (throttle lock control (N/C)). The correct resistance measurement is less than five Ohms.
Toggle the throttle lock switch to the ON position. Hold the switch in this position while the measurements are being taken.
Measure the resistance between terminals P1-5 (digital sensor return) and P1-45 (throttle lock control (N/C)). The correct resistance measurement is an open circuit.
Measure the resistance between terminals P1-5 (digital sensor return) and P1-44 (throttle lock control (N/O)). The correct resistance measurement is less than five Ohms.
Connect the J1/P1 connectors. Expected Result:The resistance measurements are within the specifications.Results:
OK - All of the resistance measurements are within the specifications.Repair: Perform the following procedure:
Turn the keyswitch to the ON position.
Use Cat ET to check for the active 549-02 code again. Toggle the throttle lock switch and hold the switch. Check Cat ET for the code. Also, wiggle the switch harness from the switch to the ECM in order to reveal an intermittent problem. If the code does not recur, the problem is resolved. The original problem was probably caused by a poor electrical connection.If the code recurs, the ECM is not detecting the switch inputs correctly. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".STOP
Not OK - At least one of the resistance measurements is not within specifications. There is a problem in the switch or in a harness. Proceed to Test Step 4.Test Step 4. Check the Operation of the Throttle Lock Switch
Disconnect the J705/P705 throttle lock switch connectors.
On the back of the switch, measure the resistance between terminals J705-1 (throttle lock control (N/C)) and P705-2 (digital sensor return). The correct resistance measurement is less than five Ohms.
Measure the resistance between terminals P705-2 (digital sensor return) and P705-3 (throttle lock control (N/O)). The correct resistance measurement is an open circuit.
Toggle the throttle lock switch to the ON position. Hold the switch in this position while the measurements are being taken.
Measure the resistance between P705-2 (digital sensor return) and P705-3 (throttle lock control (N/C)). The correct resistance measurement is less than five Ohms.
Measure the resistance between P705-1 throttle lock control (N/C) and P705-2 digital sensor return. The correct resistance measurement is an open circuit. Expected Result:The resistance measurements are within the specifications.Results:
OK - The switch is OK. There is a problem in a wiring harness. There may be a problem in a conne