DTC Advanced Diagnostics: P2127, P2128
DTC P2127:Accelerator Pedal Position (APP) Sensor B (Throttle Position (TP) Sensor E) Circuit Low Voltage
DTC P2128:Accelerator Pedal Position (APP) Sensor B (Throttle Position (TP) Sensor E) Circuit High Voltage

General Description

Accelerator pedal position (APP) sensor B 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 B is a set value, the PCM detects a malfunction and stores a DTC.

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

Enable Conditions
Condition
 
Vehicle
ON mode

Malfunction Threshold
DTC: P2127

The APP sensor B output voltage [APP SENSOR B] is 0.2 V or less for at least 200 milliseconds.

DTC: P2128

The APP sensor B output voltage [APP SENSOR B] is 4.0 V or more for at least 200 milliseconds.

[ ]: 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: P2127
APP sensor B APS2 line open
APP sensor B APS2 line short to ground
APP sensor B VCC line open

DTC: P2128
APP sensor B APS2 line short to APP sensor B VCC line
APP sensor B SG line open

Common
APP sensor B failure
PCM internal circuit failure

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 or by disconnecting the 12 volt battery.