Contaminated or sticking throttle body due to carbon buildup, preventing the throttle plate from reaching its full stop; Worn or misadjusted accelerator pedal position sensor or its mechanical linkage; Damaged or corroded wiring harness or connector at the throttle body or pedal sensor; Failed throttle position sensor or accelerator pedal position sensor; Faulty throttle actuator control motor or its circuit; ECM software calibration issue requiring an update; Mechanical binding in the accelerator pedal assembly or throttle cable (on older vehicles)

DTC codes / P21xx · Fuel and air metering / P2163

P2163Throttle/Pedal Position Sensor 'A' Maximum Stop Performance

Q: What does code P2163 mean?

Throttle/Pedal Position Sensor 'A' Maximum Stop Performance. P2163 indicates that the engine control module (ECM) has detected a performance problem with the maximum stop of throttle or pedal position sensor 'A'. The ECM expects the sensor's signal to reach a specific maximum value when the throttle is fully depressed, but the signal does not meet that expectation during the self-test or during normal operation.

P2163 indicates that the engine control module (ECM) has detected a performance problem with the maximum stop of throttle or pedal position sensor 'A'. The ECM expects the sensor's signal to reach a specific maximum value when the throttle is fully depressed, but the signal does not meet that expectation during the self-test or during normal operation.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode when the accelerator pedal is pressed firmly
Hesitation or lack of response when accelerating from a stop
Inconsistent idle speed or stalling when coming to a stop
A stored trouble code in the ECM with freeze frame data showing the fault occurred during a full throttle event

Common causes, most likely first

Contaminated or sticking throttle body due to carbon buildup, preventing the throttle plate from reaching its full stop
Worn or misadjusted accelerator pedal position sensor or its mechanical linkage
Damaged or corroded wiring harness or connector at the throttle body or pedal sensor
Failed throttle position sensor or accelerator pedal position sensor
Faulty throttle actuator control motor or its circuit
ECM software calibration issue requiring an update
Mechanical binding in the accelerator pedal assembly or throttle cable (on older vehicles)

How to diagnose and fix it

Connect a scan tool and record freeze frame data to see the sensor voltages at the time of the fault
Visually inspect the throttle body for carbon buildup and clean it with approved throttle body cleaner
Check the accelerator pedal for full travel and ensure no floor mats or obstructions prevent full depression
Inspect the wiring and connectors at the throttle position sensor and accelerator pedal position sensor for damage or corrosion
Use a multimeter to verify sensor reference voltage and signal voltage through the full range of pedal travel
Perform a throttle body relearn or idle relearn procedure with a scan tool after cleaning or replacement
If the fault persists, replace the faulty sensor or throttle body assembly and recheck for codes

Common Misdiagnosis Traps for P2163

A dirty throttle body is the most frequent cause of this code, yet many technicians replace the accelerator pedal sensor first without checking for carbon buildup on the throttle plate.
The code can be set by a driver who never fully depresses the accelerator pedal during normal driving, so the ECM may not see the expected maximum stop value during a self-test.
After cleaning or replacing the throttle body, a relearn procedure is often required; skipping it can cause the code to return immediately.
Wiring harness chafing near the throttle body or pedal assembly can intermittently short or open the sensor signal, mimicking a failed sensor.
On some vehicles, a weak battery or poor ground can cause erratic sensor readings that trigger P2163 without any actual sensor fault.

Can I keep driving with P2163?

The vehicle may enter limp mode and limit power, which can be unsafe in traffic, so avoid full-throttle acceleration and plan to have the fault diagnosed soon. If the check engine light is flashing or the vehicle barely accelerates, stop driving and seek professional assistance.

Tools that help

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