DTC Advanced Diagnostics: P2121
DTC P2121:Accelerator Pedal Position (APP) Sensor A (Throttle Position (TP) Sensor D) Out of Range

General Description

Accelerator pedal position (APP) sensor A is a part of the electronic throttle control system. It is used to convert the position of the accelerator pedal into electrical signals. Based on these signals, the powertrain control module (PCM) controls the throttle actuator so that the throttle position agrees with the accelerator pedal position. If the signal voltage from APP sensor A is a set value for a specified time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
6 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
  
Vehicle
ON mode

Malfunction Threshold
The APP sensor A output voltage [APP SENSOR A] is 0.69 V or less, or 4.99 V or more for at least 6 seconds.

[ ]: 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.
APP sensor A failure
PCM internal circuit failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

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 or by disconnecting the 12 volt battery.