P2129

Throttle/Pedal Position Sensor/Switch E Circuit Intermittent

Q: Is it safe to drive with P2129?

Usually short-term, but because the fault is intermittent the throttle can drop into reduced power at random. Have it diagnosed before relying on the car in traffic.

Q: Can I just clear P2129?

You can, but an intermittent wiring or connector fault will set it again. The real fix is finding and repairing the loose or chafed connection.

Throttle / air metering Generic OBD-II Medium

What it means

P2129 means the ECM saw an intermittent or erratic signal from throttle/pedal position sensor "E." Because the reading comes and goes, the fault points strongly at a wiring or connector problem rather than a constant sensor failure. On drive-by-wire systems these dropouts can briefly cut power or trigger limp mode, so it's worth chasing down even if the car mostly drives normally.

Medium

Can I keep driving? Often driveable, but an intermittent pedal/throttle signal can cause sudden reduced-power or limp mode without warning — get it checked soon.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Intermittent reduced power or limp (failsafe) mode
Surging or inconsistent throttle response
Rough or unstable idle at times

Common causes

Most likely first

Loose, corroded, or poor connector at the sensor (most common with an intermittent fault)Likely
Chafed, open, or intermittently shorted wiring in the 'E' sensor circuitCommon
Faulty throttle/pedal position sensor ECommon
Faulty engine control module (ECM) — rareLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data, then wiggle-test the sensor connector and harness while watching live data for signal dropouts.
Inspect the connector and pins for corrosion, spread terminals, or a loose fit; reseat or repair as needed.
Check the circuit for a steady 5-volt reference and clean ground, and look for chafed wiring.
If the signal still drops out, replace the position sensor and clear the code.

FAQ

Quick answers

Is it safe to drive with P2129?+

Usually short-term, but because the fault is intermittent the throttle can drop into reduced power at random. Have it diagnosed before relying on the car in traffic.

Can I just clear P2129?+

You can, but an intermittent wiring or connector fault will set it again. The real fix is finding and repairing the loose or chafed connection.

Read & clear P2129 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX