PISTON 4J9981 - Caterpillar

Table 1
J1939 Code and Description Comments
51-2
Engine Throttle Position : Erratic, Intermittent, or Incorrect The ECM has been notified by the throttle actuator that the actuator self calibration is in progress or has not calibrated at device power ON.
51-7
Engine Throttle Position : Not Responding Properly The ECM has been notified by the throttle actuator that the valve is not able to reach the commanded valve position.
51-12
Engine Throttle Position : Failure The ECM has been notified by the throttle actuator that an internal failure has occurred.
51-13
Engine Throttle Position : Out of Calibration The ECM has been notified by the throttle actuator that the self-calibration at device power-up has failed.
Engine cranking will be inhibited until calibration is resolved.
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 -7 code is active.
Proceed to Test Step 2.
Result: A -2,-12, or -13 code is active.
Proceed to Test Step 3.
2. Check for Binding of the Throttle Actuator
A. Set the engine control to the OFF/RESET mode.
B. Remove the electrical power from the engine.
C. Move the throttle plate while you feel the motion. If the motion is sticky and/or rough, investigate the cause of the binding. Make the necessary repairs.
Binding
Result: The actuator throttle plate movement is OK .
Proceed to Test Step 3.
Result: The actuator throttle plate is NOT OK.
Repair: Remedy the cause of the binding. If necessary, replace the throttle actuator.
3. Cycle Battery Power
A. Turn the main disconnect t switch to the OFF position for at least 30 seconds.
B. Turn the battery disconnect switch to the ON position.
Cycle Power
Result: A -2,-7, -12, or -13 code is active after cycling power to the device.
Repair: Replace the throttle actuator valve.
Result: The active diagnostic has transitioned to logged.
There may have been an intermittent electrical problem with the actuator. If diagnostic code continues to return to an active status, replace the throttle actuator valve.