Worn or contaminated accelerator pedal position sensor 2 inside the pedal assembly; Corroded, loose, or damaged electrical connector at the APP sensor or throttle body; Chafed or open wiring in the APP sensor 2 signal or ground circuit; Failed or failing throttle actuator control module or PCM software calibration issue; Poor ground connection shared by the APP sensors and other engine sensors; Aftermarket floor mats or debris obstructing full pedal travel and skewing sensor 2 readings

DTC codes / GM codes / P1281

P1281 · GMAccelerator Pedal Position (APP) Sensor 2 Performance

Q: What does code P1281 mean?

Accelerator Pedal Position (APP) Sensor 2 Performance. P1281 on GM vehicles indicates that the powertrain control module has detected a performance problem with the second accelerator pedal position sensor, which is the backup signal used to cross-check the primary pedal sensor. The computer compares the two APP sensor voltages and flags this code when the second sensor's signal is out of expected range, erratic, or disagrees with sensor 1 beyond a calibrated tolerance.

P1281 on GM vehicles indicates that the powertrain control module has detected a performance problem with the second accelerator pedal position sensor, which is the backup signal used to cross-check the primary pedal sensor. The computer compares the two APP sensor voltages and flags this code when the second sensor's signal is out of expected range, erratic, or disagrees with sensor 1 beyond a calibrated tolerance.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illuminated check engine light or reduced engine power message on the driver information center
Throttle pedal feels unresponsive or the engine hesitates when accelerating
Vehicle may enter limp mode with limited engine speed and power
Intermittent surging or stumbling during light throttle application
Often no symptoms besides the warning light, especially if the fault is intermittent
Cruise control may become inoperative or disengage unexpectedly

Common causes, most likely first

Worn or contaminated accelerator pedal position sensor 2 inside the pedal assembly
Corroded, loose, or damaged electrical connector at the APP sensor or throttle body
Chafed or open wiring in the APP sensor 2 signal or ground circuit
Failed or failing throttle actuator control module or PCM software calibration issue
Poor ground connection shared by the APP sensors and other engine sensors
Aftermarket floor mats or debris obstructing full pedal travel and skewing sensor 2 readings

How to diagnose and fix it

Inspect the accelerator pedal area for aftermarket floor mats, debris, or obstructions that limit pedal travel and clear anything found
Use a scan tool to read live APP sensor 1 and sensor 2 voltages through the full pedal sweep and compare them for smooth, proportional tracking
Visually inspect the APP sensor connector and harness for corrosion, pushed pins, or chafed wires, and repair any damage found
Check the APP sensor ground circuit for excessive resistance and verify the reference voltage at the sensor connector
Perform a wiggle test on the APP harness while watching live data to expose intermittent signal dropouts
If sensor 2 voltage is erratic or out of range while sensor 1 tracks correctly, replace the accelerator pedal assembly and relearn the pedal position
Clear the code and verify the repair by completing a full drive cycle with live data monitoring to confirm no return of the fault

What a P1281 really tells you

P1281 is almost always a circuit or sensor signal integrity fault rather than a mechanical throttle body failure, so replacing the throttle body first is a common and expensive misdiagnosis.
The two APP sensors are designed to produce voltages that track proportionally but are not identical, so comparing them with a voltmeter instead of a scan tool often leads to false conclusions.
A weak or shared ground on the APP sensor circuit can set P1281 intermittently and is frequently overlooked because the connector looks clean and tight.
Aftermarket floor mats or a pedal that cannot return fully to rest can skew sensor 2 readings enough to set this code without any actual electrical fault.
On some GM platforms a software calibration update for the throttle actuator control module resolves repeat P1281 codes after all wiring and sensor checks pass.

Can I keep driving with P1281?

You can usually drive the vehicle to a repair shop, but expect reduced engine power and avoid heavy acceleration, highway merging, or towing until the fault is repaired. If the vehicle repeatedly enters limp mode or the pedal response becomes unpredictable, stop driving and arrange a tow.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.