COVER AS-CYLINDER 1566992 - Caterpillar

Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the terminal connections on the P1/J1 ECM connector and the analog throttle position sensors.
Refer to Troubleshooting, "Electrical Connector - Inspect".
B. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the analog throttle position sensor connectors that are associated with the active diagnostic code.
C. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
D. Check the harness for corrosion, abrasion, and pinch points from the analog throttle position sensors 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 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 for Active Diagnostic Codes
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. Wait at least 10 seconds for activation of the diagnostic codes.
D. Verify if any of the diagnostic codes that are listed in Table 1 are active.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: There are no active diagnostic codes for the analog throttle position sensors.
Proceed to Test Step 3.
Result: One or more of the diagnostic codes listed in Table 1 is active.
Proceed to Test Step 5.
3. Check the Throttle Position with the Electronic Service Tool
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position. Do not start the engine.
C. Observe the throttle position reading on the electronic service tool.
D. Operate the throttle over the full range of movement.
20 percent to 27 percent at low idle.
80 percent to 87 percent at high idle
Result: The ECM is not receiving the correct signal from the sensor.
Repair: Use the electronic service tool to verify that the throttle has been configured correctly before continuing with this procedure.
If the fault is still present after the throttle has been configured correctly, replace the analog throttle position sensor.
Result: The sensor is operating correctly.
Proceed to Test Step 4.
4. Check the Throttle Selection Status with the Electronic Service Tool
A. Check the status of the throttle selection switch (if equipped). Use the electronic service tool to check the status of the throttle selection switch.
Throttle 1 has control when status is "OFF".
Throttle 2 has control when status is ON.
Result: The throttle section switch is operating correctly.
Return the engine to service.
If an intermittent fault exists, refer to Troubleshooting, "Electrical Connector - Inspect"
Result: The wrong throttle is selected.
Repair: Switch to the other throttle. There may be a fault with the selector switch input.
Check the connections between the throttle selection switch and the P1