P2139

Throttle/Pedal Position Sensor/Switch D/F Voltage Correlation

Q: Is it safe to drive with P2139?

Only cautiously. The two disagreeing signals usually force reduced power for safety, so acceleration is limited — avoid highway merging until it's repaired.

Q: Can I just clear P2139?

It returns as soon as the sensors disagree again. The two signals must track together correctly, which means fixing the sensor or its wiring.

Throttle / air metering Generic OBD-II Medium

What it means

P2139 means two of the redundant throttle/pedal position signals ("D" and "F") don't agree with each other. These sensors are doubled up for safety, so when their voltages don't correlate the ECM can't trust the pedal input and usually defaults to reduced power. The cause is typically a failing sensor or wiring fault between the circuits, not an engine mechanical problem.

Medium

Can I keep driving? Commonly triggers a reduced-power limp mode as a safety default — driveable gently, but acceleration is limited, so fix it before highway use.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Appears alongside · share of P2139 scans

P2132in 83.8% of scans

P2122in 82.3% of scans

P2127in 82.3% of scans

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
Reduced power / forced limp (failsafe) mode
Poor or inconsistent throttle response
Hesitation or surging on acceleration

Common causes

Most likely first

Faulty pedal/throttle position sensor (D or F element disagreeing)Likely
Open, shorted, or chafed wiring between the two sensor circuitsCommon
Poor or corroded connector at the pedal or throttle sensorCommon
Faulty engine control module (ECM) — rareLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data, then compare the D and F signals in live data to see which one is out of range.
Inspect the connector and wiring for corrosion, damage, or shared-circuit shorts.
Verify each circuit has its 5-volt reference and clean ground, key on.
If the two signals won't track together after wiring is confirmed good, replace the pedal/throttle position sensor.

FAQ

Quick answers

Is it safe to drive with P2139?+

Only cautiously. The two disagreeing signals usually force reduced power for safety, so acceleration is limited — avoid highway merging until it's repaired.

Can I just clear P2139?+

It returns as soon as the sensors disagree again. The two signals must track together correctly, which means fixing the sensor or its wiring.

Read & clear P2139 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