CONTROL GP-SERVICE BRAKE 1674425 - Caterpillar

Illustration 1 g03733170
Schematic for the PTO switches
Not all connectors are shown. Refer to the appropriate Electrical Schematic.
Table 1
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Thoroughly inspect the J1/P1 connectors on the Electronic Control Module (ECM), the switch connections and battery connections. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the switch connector and the ECM connector that are associated with the active diagnostic code. Refer to Illustration 1.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the harness for corrosion, abrasion, and pinch points from the PTO mode switches to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Check the "PTO Mode Switches" on the Electronic Service Tool
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position.
D. Observe the status of the PTO mode switch on the electronic service tool while cycling the PTO ON/OFF switch.
E. Use the electronic service tool in order to observe the status of the PTO mode switch while cycling the PTO Set/Lower switch.
F. Use the electronic service tool in order to observe the status of the PTO mode switch while cycling the PTO Raise/Resume switch.
Switch status changes from "OPEN" to "CLOSED"
Result: The switch status changes on the electronic service tool as the PTO switches are cycled.
Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service.
Result: The switch status does not change as the PTO switches are cycled.
Proceed to Test Step 3.
3. Check the Status of the PTO Mode Disengage Switches
A. Use the electronic service tool in order to observe the switch status while the PTO mode disengage switches are operated OFF and ON.
Note: The PTO mode - Disengage switches usually function by the operation of the brake, clutch, or the operator switch. These switches should be operated separately for this test.
Switch status changes from "ENGAGED" to "DISENGAGED"
Result: The PTO mode - Disengage switch operates correctly.
Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service.
Result: The PTO mode - Disengage switch does not operate correctly.
Proceed to Test Step 4.
4. Check the Suspect PTO Switch
A. Turn the keyswitch to the OFF position.
B. Remove the two wires from the suspect switch. Use a suitable jumper in order to join the two wires together.
C. Turn the keyswitch to the