DTC Advanced Diagnostics: P2122, P2123
DTC P2122:Accelerator Pedal Position (APP) Sensor A (Throttle Position (TP) Sensor D) Circuit Low Voltage
DTC P2123:Accelerator Pedal Position (APP) Sensor A (Throttle Position (TP) Sensor D) Circuit High Voltage

General Description


Accelerator pedal position (APP) sensor A and accelerator pedal position (APP) sensor B determine the position of the accelerator pedal. At the same mechanical position, the signal voltage of APP sensor B is always by factor 2 smaller than the voltage of APP sensor A. By different checks it is guaranteed that on account of a single fault, the pedal value cannot be higher than the corresponding mechanical position of the accelerator pedal. Circuit continuity check and synchronization check are done at the powertrain control module (PCM). For the circuit continuity check, the voltage of both APP sensors is compared with an upper and lower thresholds. If the voltage value is not within a specified range, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
0.2 second or more
DTC Type
One drive cycle, MIL on

Enable Conditions
Condition
 
State of the engine
Running
 

Malfunction Threshold
DTC: P2122

The APP sensor A output voltage [APP Sensor A] is 0.4 V or less for at least 0.2 second.

DTC: P2123

The APP sensor A output voltage [APP Sensor A] is 4.822 V or more for at least 0.2 second.

[ ]: HDS Parameter

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
DTC: P2122
APP sensor A APS1 line short to ground
APP sensor A APS1 line open
APP sensor A VCC line open

DTC: P2123
APP sensor A APS1 line short to power
APP sensor A SG line open

Common
APP sensor A failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine, and let it idle.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.