SUPPORT ASSEM 1P7590 - Caterpillar

Use this procedure to troubleshoot a problem with the throttle actuator. Also, use this procedure if the following diagnostic code is active or easily repeated.
Table 1
J1939 Codes and Description Comments
3464–8
Engine Throttle Actuator 1 Control Command : Abnormal Frequency, Pulse Width, or Period The actuator has detected an error in the Pulse Width Modulated (PWM) signal that is from the Electronic Control Module (ECM).
The code is logged.
The engine is shutdown.
5419–12
Engine Throttle Actuator #1 : Failure During a self-test the actuator has detected an internal fault.
The code is logged.
The engine is shutdown. The engine throttle actuator is an electronic actuator. The throttle actuator works with the Electronic Control Module (ECM) to ensure that the correct commanded position is present during all engine operating conditions.The ECM modulates the throttle actuator from a fully closed position to a fully opened position.The PWM range of 5 percent to 95 percent is scaled to 0 percent to 100 percent of the "Desired Valve Position".
Illustration 1 g06024004CommunicationsThe ECM and the throttle actuator communicate via the CAN data link. The ECM sends a command signal to the actuator. The actuator sends the actual valve position and internal fault diagnosis information to the ECM.If the ECM cannot communicate with the throttle actuator, the ECM activates a 51-9 diagnostic code. The problem may be with the power supply to the throttle actuator. This code may be generated for an intermittent problem. After checking the power circuit for the actuator, refer to Troubleshooting , CAN Data Link - Test for information that is related to troubleshooting the data link circuitry.
Illustration 2 g06137092
For the complete circuit details, refer to the full schematic.
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: A 3464–8 code is active or logged.
Proceed to Test Step 2.
Result: A 5419–12 code is active or logged.
Repair: The engine throttle actuator has detected an internal problem with the actuator electronics. Replace the engine throttle actuator.
2. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Perform a 45 N (10 lb) pull test on the connector wires.
D. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 3.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Wiring for an Open Circuit
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the A-C1 and A-C2 wiring harness connectors from the ECM.
C. Disconnect the throttle actuator connector.
D. Measure the resistance between the following locations:
- Terminal R (PWM +) of the throttle actuator