Cause
Throttle or pedal position sensor drift
A throttle or accelerator pedal sensor whose output has moved away from what the module was taught to expect. These are the most safety-monitored sensors on the engine, because there is no cable between the pedal and the throttle any more — the connection is entirely a number, and a wrong number means an engine producing torque nobody asked for.
Which is why both sensors are doubled. The pedal and the throttle body each carry two independent tracks, deliberately given different slopes or offsets so they can never agree by accident. The module continuously checks that the pair disagree in exactly the expected way, and drift on one track breaks that relationship long before either reading looks obviously wrong on its own.
The mechanism is usually mechanical wear on a resistive track — a worn spot at the idle position, where the wiper has rested for most of the sensor's life. That is why symptoms cluster at small openings: a hesitation just off idle, or a stumble pulling away, on a car that is fine at larger throttle openings. Contactless sensors avoid this and drift for other reasons, usually magnet ageing or heat.
Expect the response to be blunt. A failed plausibility check cuts throttle authority hard and drops the engine into a heavily limited mode — deliberately, because the alternative is unintended acceleration. Many vehicles need a throttle relearn after any repair here, and skipping it leaves the fault apparently unfixed.
Typically a moderate job.
Some of these codes mean you should stop driving
1 of the 7 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (7)
Codes where this is a likely explanation first, rather than merely a possible one.
- P061B Internal Control Module Torque Calculation Performance Likely for this code Stop driving High
- P2164 Throttle/Pedal Position Sensor B Maximum Stop Performance Likely for this code Moderate
- P2165 Throttle/Pedal Position Sensor C Maximum Stop Performance Likely for this code Moderate
- P2166 Throttle/Pedal Position Sensor D Maximum Stop Performance Likely for this code Moderate
- P2167 Throttle/Pedal Position Sensor E Maximum Stop Performance Likely for this code Moderate
- P2168 Throttle/Pedal Position Sensor F Maximum Stop Performance Likely for this code Moderate
- P050A Cold Start Idle Control System Performance Moderate
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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