The Lemon IndexThe throttle position reading doesn't make sense for the conditions.
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
Failing throttle position sensor. Then: dirty throttle body; wiring fault.
Owners named P0121 in 26 complaints to the U.S. government, most often on the Chevrolet Traverse.
Cars owners report it on
Complaints that name P0121, by model. Raw counts, not a failure rate: popular models get more complaints.
Years owners report it on most: 2005 Ford F-Series · 2011 Chevrolet Traverse
The details
What P0121 means
The throttle position reading doesn't make sense for the conditions. Hesitation or reduced power is common.
Can I drive with P0121?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
27% of the owner complaints that name P0121 also say the car stalls or shuts off. A complaint can describe more than one problem, so this doesn't prove the code caused it.
Common causes of P0121
- Failing throttle position sensor
- Dirty throttle body
- Wiring fault
A shop should confirm the cause with a scan and tests before replacing parts.
What owners describe
- Stalls or shuts off: 27% of complaints
- Warning lights and electrical faults: 23% of complaints
- Loses power or goes into limp mode: 19% of complaints
- Brakes or ABS act up: 12% of complaints
Share of complaints naming the code whose text also mentions each problem.
Model years that report P0121 most
2005 Ford F-Series (2), 2011 Chevrolet Traverse (2).
Related codes
P0120 P0122 P0123 P0126 P0128 P0117 P0113 P0131
Quick answers
What does P0121 mean?
Throttle/Pedal Position Sensor A Range/Performance. The throttle position reading doesn't make sense for the conditions. Hesitation or reduced power is common.
Can I drive with P0121?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
What causes P0121?
Failing throttle position sensor; Dirty throttle body; Wiring fault.
Counts: NHTSA owner complaints whose text names P0121. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.