Worn or contaminated accelerator pedal position sensor 2 inside the pedal assembly; Corroded or backed-out terminals at the pedal sensor connector; Chafed or broken wire in the sensor 2 signal or ground circuit; Poor ground connection shared by the pedal sensors; Failing throttle actuator control module or PCM driver for the sensor 2 circuit; Aftermarket floor mats or debris obstructing full pedal travel and skewing sensor correlation

DTC codes / GM codes / P1280

P1280 · GMAccelerator Pedal Positioning Sensor 2 Circuit

Q: What does code P1280 mean?

Accelerator Pedal Positioning Sensor 2 Circuit. P1280 on a GM vehicle indicates that the powertrain control module has detected an out-of-range or implausible signal from the accelerator pedal position sensor 2 circuit. The computer compares this signal against sensor 1 and expects a specific voltage relationship, so a deviation triggers the code and typically forces the engine into reduced power mode.

P1280 on a GM vehicle indicates that the powertrain control module has detected an out-of-range or implausible signal from the accelerator pedal position sensor 2 circuit. The computer compares this signal against sensor 1 and expects a specific voltage relationship, so a deviation triggers the code and typically forces the engine into reduced power mode.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Reduced engine power message on the driver information center with limited throttle response
Engine idle that hangs high or fluctuates without pedal input
Hesitation or stumble when pressing the accelerator from a stop
Cruise control that disengages or fails to set
Often no symptoms besides the warning light if the fault is intermittent

Common causes, most likely first

Worn or contaminated accelerator pedal position sensor 2 inside the pedal assembly
Corroded or backed-out terminals at the pedal sensor connector
Chafed or broken wire in the sensor 2 signal or ground circuit
Poor ground connection shared by the pedal sensors
Failing throttle actuator control module or PCM driver for the sensor 2 circuit
Aftermarket floor mats or debris obstructing full pedal travel and skewing sensor correlation

How to diagnose and fix it

Scan all modules for stored and pending codes, then record freeze-frame data for P1280 and any throttle-related codes
Inspect the accelerator pedal connector and harness for corrosion, loose pins, or chafing, and repair as needed
Back-probe sensor 2 signal and ground wires and compare voltages through the full pedal sweep against sensor 1
Check the pedal sensor ground circuit for excessive voltage drop under load
Verify sensor 2 voltage with a scan tool while slowly pressing and releasing the pedal to catch intermittent dropouts
Replace the accelerator pedal assembly if sensor 2 output is erratic or outside the specified correlation window
Clear codes and perform a throttle body and pedal relearn procedure, then road test to confirm the repair

Why P1280 is often a pedal assembly fault

The two pedal sensors are designed to produce opposite voltage sweeps, so a single lazy sensor 2 is far more common than a wiring failure and usually condemns the whole pedal assembly.
A dirty throttle body can set P1280 indirectly by causing the PCM to question pedal correlation, so clean and relearn the throttle before replacing the pedal.
Intermittent P1280 codes often leave no freeze-frame data, making a slow pedal sweep with a scan tool connected the only reliable way to catch the dropout.
Aftermarket floor mats or a bent pedal arm can prevent full travel and set this code even though the sensor itself is healthy.
A weak battery or poor chassis ground can cause phantom pedal codes on GM trucks, so verify charging voltage before condemning the sensor.

Can I keep driving with P1280?

You can usually limp the vehicle to a shop, but expect reduced power and avoid highways or heavy traffic because throttle response may be unpredictable. If the pedal feels dead or the engine idles high on its own, stop driving and have it towed.

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.