P2129 code meaning
Throttle/Pedal Position Sensor/Switch E Circuit Intermittent
Powertrain system Generic code P21xx codes Check engine light
What P2129 means
P2129 is meant for short dropouts or spikes in signal circuit E that do not last long enough for a steady low or high fault. No manufacturer documents this code publicly. GM and Ford, which assign E to the second pedal sensor, catch such glitches inside their circuit codes instead: GM counts failures every 12.5 ms and flags the APP sensor 2 circuit after 19 of 39 counts (P2125/P2127/P2128), Ford uses 0.25/4.75 V limits. CARB requires circuit monitoring of input sensors; the code fits that duty. Check for loose pins and harness chafing with the pedal moved slowly. Effects range from a warning lamp to brief power cuts while driving.
P2129 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2129
- Warning lamp that comes and goes
- Brief hesitation or power loss while driving
- Reduced power mode after repeated dropouts
Common causes of P2129
- Most likelyLoose terminal or poor pin tension at the pedal connector
- PossibleChafed harness making intermittent contact
- PossibleWorn spot or cracked joint inside the pedal sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Accelerator pedal position sensorPedal sensor wiringECM
What each part of P2129 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 1 | Area: fuel and air metering. |
| 29 | The exact fault in that area. |
What to do next
- Note P2129 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2129
What does P2129 mean?
P2129 means "Throttle/Pedal Position Sensor/Switch E Circuit Intermittent". P2129 is meant for short dropouts or spikes in signal circuit E that do not last long enough for a steady low or high fault. It is a generic code, so it means the same on every make.
Is it safe to drive with P2129?
Drive gently and only to a workshop. With P2129 the car can go into limp mode (reduced power) to protect itself.
Will P2129 fail an emissions test?
Yes, it can. P2129 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2129 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2129 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.