PLUG 1474237 - Caterpillar

System Operation Description:Use this procedure under the following situation:Use this procedure to determine if the clutch pedal position switch is operating properly.The clutch pedal position switch is normally closed when the pedal is released. Depressing the clutch pedal should open the circuit. This switch is OEM supplied. The clutch pedal position switch is typically a limit switch that is mounted near the pedal. The clutch pedal position switch is usually adjustable.This switch may not be connected to an input on the Engine Control module (ECM). The parameter "Clutch Pedal Position Switch" determines the input to the ECM. If the parameter is programmed to J1/P1:22 a switch must be connected to terminal 22. If the parameter is programmed to one of the J1939 options, the switch position will be transmitted to the ECM over the J1939 data link. If a problem is suspected with the J1939 data link, refer to Troubleshooting, "Powertrain Data Link Circuit - Test".
Illustration 1 g00862119
This is a typical circuit schematic for the clutch pedal position switch.
The return wire may be connected to P1-3, P1-5, or P1-18.
Test Step 1. Inspect Electrical Connectors and Wiring
Illustration 2 g01150942
Pin locations on the ECM connector
(P1-5) AP sensor/switch common
(P1-22) Clutch pedal position switch
Thoroughly inspect ECM vehicle harness connector J1/P1, the firewall bulkhead connector and the terminals for the following switches in the connectors:
J1/P1-22 (clutch pedal position switch)
J1/P1-5 (AP sensor/switch common)Refer to Troubleshooting, " Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the switches. Refer to Illustration 2.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasion and pinch points from the sensor to the ECM. Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - 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 Clutch Switch Status on Caterpillar Electronic Technician (ET)
Table 1
Status of the Clutch Pedal Position Switch
Switch Position or Pedal Position Status Circuit
The clutch pedal is depressed. ON Open
The clutch pedal is released. OFF Closed
Connect Cat ET to the cab data link connector. Access the status screen.
Turn the ignition key switch to the ON position.
Depress the clutch pedal while the status of the clutch pedal position switch is being observed. Also, release the clutch pedal while the status of the clutch pedal position switch is being observed. Expected Result:The switch status changes per the information in Table 1.Results:
Yes - The switch is operating normally.STOP
No - The ECM is not reading the switch status change. Proceed to Test Step 3.Test Step 3. Check the Switch Circuit for the ECM
Table 2
Status of the Clutch Switch
Condition