P0123-TPS/APP CIRCUIT HIGH





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The Accelerator Pedal Position Sensor (APPS) is a linear potentiometer. It provides the ECM and the TCM with a voltage signal proportional to the angle, or position of the accelerator pedal. The APPS signal along with inputs from other sensors is used by the ECM and the TCM to calculate the throttle position.


  • When Monitored:

    Continuously with the ignition on and engine running.

  • Set Condition:

    This DTC will set if the monitored TPS voltage rises above 4.94 volts for the period of 0.48 seconds.


Possible Causes
  
RELATED ENGINE TPS/APPS DTC'S PRESENT
  
(K23) APP SENSOR 1 SIGNAL CIRCUIT SHORT VOLTAGE
  
(K167) APP SENSOR 1 GROUND CIRCUIT OPEN
  
ACCELERATOR PEDAL POSITION SENSOR
  
TRANSMISSION CONTROL MODULE
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)



Diagnostic Test

1.CHECK IF RELATED ENGINE TPS/APPS DTC'S ARE PRESENT



Are there any Engine TPS/APPS DTCs present?

Yes


No
  • Go To 2

2.CHECK TO SEE IF THE DTC IS CURRENT



Is the TPS/APPS voltage above 4.94 volts?

Yes
  • Go To3


No
  • Go To5

3.ACCELERATOR PEDAL POSITION SENSOR






Is the TPS/APPS voltage below 0.5 volts?

Yes
  • Go To 4


No

4.(K167) APP SENSOR 1 GROUND CIRCUIT OPEN





Is the resistance above 5.0 ohms?

Yes


No
  • Using the schematics as a guide, check the Engine Control Module (ECM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ECM per the Service Information. With the scan tool, perform QUICK LEARN.
  • Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

5.INTERMITTENT WIRING AND CONNECTORS






Were there any problems found?

Yes


No
  • Test Complete.