P2122-ACCELERATOR PEDAL POSITION SENSOR 1 CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W.


  • When Monitored:

    With the ignition on and no other APPS No.1 DTCs present.

  • Set Condition:

    When the APP Sensor No.1 voltage is too low. Engine will additionally idle if the brake pedal is pressed or has failed. Acceleration rate and Engine output are limited. One trip fault and the code will set within 5 seconds. ETC light is flashing.


Possible Causes
 
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
 
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
 
(K23) APP SIGNAL 1 CIRCUIT OPEN
 
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO GROUND
 
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (K167) APP RETURN 1 CIRCUIT
 
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (K400) APP RETURN 2 CIRCUIT
 
APP SENSOR
 
PCM
 


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1.APP SENSOR BELOW 0.25 OF A VOLT

NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.





Is the voltage below 0.25 of a volt?

Yes
  • Go To 2


No

2.(F855) 5-VOLT SUPPLY CIRCUIT








Is the voltage between 4.5 and 5.2 volts?

Yes
  • Go To 3


No
  • Go To 8

3.ACCELERATOR PEDAL POSITION SENSOR






Is the voltage above 4.5 volts?

Yes
  • Replace the APP Sensor Assembly per Service Information. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
  • Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)


No
  • Go To 4
  • NOTE: Remove the jumper wire before continuing.


4.(K23) APP SIGNAL 1 CIRCUIT OPEN





CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.




Is the resistance below 5.0 ohms?

Yes
  • Go To 5


No

5.(K23) APP SIGNAL 1 CIRCUIT SHORTED TO GROUND





Is the resistance below 100 ohms?

Yes


No
  • Go To 6

6.(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (K167) APP RETURN 1 CIRCUIT





Is the resistance below 100 ohms?

Yes


No
  • Go To 7

7.(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (K400) APP RETURN 2 CIRCUIT





Is the resistance below 100 ohms?

Yes


No

8.(F855) 5-VOLT SUPPLY CIRCUIT OPEN





CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.




Is the resistance below 5.0 ohms?

Yes
  • Go To 9


No

9.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





Is the resistance below 100 ohms?

Yes


No

10.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.




Were there any problems found?

Yes


No

11.APP SENSOR SWEEP





Does voltage start at approximately 0.45 of a volt and go above 4.6 volts with a smooth transition?

Yes


No
  • Replace the APP Sensor Assembly per Service Information. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
  • Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)