P2127

Throttle/Pedal Position Sensor/Switch E Circuit Low

Throttle / pedal position Generic OBD-II Medium

What it means

P2127 means the PCM sees the "E" throttle/pedal position sensor signal reading too low — usually a short to ground, an open reference wire, or a failing sensor. Because the PCM relies on this signal to judge driver demand, it often limits power until the circuit reads correctly again.

Medium

Can I keep driving? Usually driveable, but the car may fall into reduced power or limp mode, so keep speeds moderate until it's repaired.

Real-world scan data

Seen in

2,142

scans in the past year

Found in

0.3%

of scans

0.6%

of scans that found faults

Appears alongside · share of P2127 scans

P2122in 63.5% of scans

P0222in 25.3% of scans

P0123in 18.4% 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 engine power / limp (failsafe) mode
Hesitation or poor throttle response
Rough or erratic idle

Common causes

Most likely first

Short to ground or open in the sensor 'E' signal or reference wiringLikely
Poor connector contact or corrosion at the sensor plugCommon
Faulty throttle/pedal position sensor 'E'Common
Faulty engine control module (ECM)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and check for companion codes (P2128, P2122, P2138).
Inspect the sensor connector and wiring for damage, corrosion, and pins pushed back.
With key on, engine off, confirm a steady 5-volt reference and a good ground; a low signal usually points to a short-to-ground or open reference.
Back-probe the signal wire and compare to spec while sweeping the pedal/throttle.
If wiring checks out, replace the position sensor; consider the ECM only after wiring and sensor are ruled out.

FAQ

Quick answers

Is it safe to drive with P2127?+

For short trips, but expect limited power. Because it involves throttle/pedal position, have it diagnosed soon.

Can I just clear P2127?+

It returns quickly if the low-voltage circuit fault is still present; fix the wiring or sensor first.

Read & clear P2127 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