Cause
Obstruction preventing full pedal travel
Something physically stopping the accelerator pedal short of its full travel, so the sensors report a maximum that is lower than the one the module expects to see. The codes name the sensors' maximum stop performance, and every sensor involved is working perfectly — they are faithfully reporting a pedal that genuinely does not go that far.
A displaced floor mat is the archetype and it deserves to be taken seriously. An overmat riding on top of the fitted mat, a mat clipped in on one side only, or one that has crept forward will foul the pedal. The same obstruction can also hold a pedal down, which is the dangerous direction and the one behind large safety recalls — so a pedal that does not return smoothly is worth more attention than a code.
Check it before any electrical work, because it costs a moment. Press the pedal to the floor by hand and feel for a stop that is soft, early, or springy rather than solid. Anything dropped into the footwell belongs on the list too — a bottle, a phone, a tool left after work under the dashboard. If the travel is genuinely full and the code persists, the fault has moved to the sensors or their calibration, and a relearn is usually the next step rather than a part.
Typically an easy fix. Often worth checking before paying anyone to look.
Some of these codes mean you should stop driving
1 of the 6 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 (6)
Codes where this is a likely explanation first, rather than merely a possible one.
- 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
- P2121 Throttle/Pedal Position Sensor/Switch D Circuit Range/Performance Stop driving High
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.
Others who found this
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Obstruction preventing full pedal travel.