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Air intakeGeneric OBD-II codeUrgency: Garage soon

Code P2127: pedal or throttle sensor "E": low signal

P2127 means: accelerator pedal position sensor or switch, or throttle "E": circuit low input.[1][2] The ECU has detected an abnormally low voltage in one of the circuits of the accelerator pedal or throttle position sensor, the one designated "E". The specific letter can mean something different depending on the manufacturer, so check the car's manual.[1]

System
Air intake
Urgency
Garage soon
You can drive carefully, but book a garage appointment as soon as possible
Possible causes
5
sorted from most to least likely
Type
Generic
The same on all makes

4 sourcesHow we work

What code P2127 means

The ECU has detected an abnormally low voltage in one of the circuits of the accelerator pedal or throttle position sensor, the one designated "E". The specific letter can mean something different depending on the manufacturer, so check the car's manual.[1]

On an electronic accelerator the pedal has a sensor with two independent signals so that the ECU can compare them. One of them is the redundant signal "E", which confirms the main one; if it drops below its minimum limit with the pedal released, the ECU discards the faulty channel and reduces engine power.[3]

Original definition (SAE J2012): Throttle/Pedal Position Sensor/Switch "E" Circuit Low[1][2]

Causes of P2127

From most to least likely, according to the sources.

  1. 1Faulty accelerator pedal position sensor.[1][2][3]
  2. 2Open circuit or short to earth in the signal circuit, or damaged, corroded or loose connectors.[1][2][3]
  3. 3Loss of the 5 V supply or of the sensor's earth.[2][3]
  4. 4Throttle sensor poorly secured or faulty, or defective throttle motor.[1][2]
  5. 5Engine ECU fault, which should only be suspected when everything else is fine.[1][2][3]

Symptoms

How to diagnose P2127

In order: from the most likely and cheapest to check to the most expensive.

  1. 1Read the codes with a diagnostic tool and note whether they appear alongside other pedal or throttle codes, which can hint at the affected circuit.[1][3]
  2. 2With the tool showing live data, watch the pedal's two signals: the low signal should rise smoothly as you press; a value stuck near zero points to an open or earthed circuit.[3]
  3. 3Inspect the pedal connector and wiring: separated or corroded terminals, moisture or chafed wires. Wiggle the harness with the ignition on to detect intermittent faults.[2][3]
  4. 4Check the sensor's 5 V supply and earth, and the continuity of the signal wire to the ECU.[3]
  5. 5If wiring, supply and earth are fine, replace the pedal assembly. Only after all of the above should the ECU be suspected.[1][3]

Can I keep driving with P2127?

Garage soon

The car usually limits power and responds poorly to the accelerator; with the engine cutting power or stalling it can be dangerous in traffic. It should be repaired before you go on using the car normally.[1][3]

Documented faults related to P2127

Known faults of specific engines and cars, with their repair cost, the affected years and their sources.

Engine sensors: the most serious faults by engine and car

All faults with the engine sensors (29)

Wiring, connectors and short circuits: the most serious faults by engine and car

All faults with the electrical wiring (160)

Frequently asked questions

Can I drive with code P2127?

You can get to the garage with care, but it is not advisable to keep using the car. It will normally go into reduced-power mode and, in the worst case, the engine may sit at idle or stall, which is a risk in traffic.[1][3]

What does the "E" in P2127 mean?

It is the letter the standard uses to designate one of the circuits of the pedal or throttle sensor. Its exact meaning can vary by manufacturer, so you need to consult the manual for the specific car.[1]

Does the accelerator pedal always need replacing?

No. The pedal is a common cause, but so are a corroded connector, a broken wire or a lost 5 V supply. It is worth testing wiring, supply and earth before replacing the assembly.[2][3]

Does P2127 mean the same on all brands?

It is a generic code, so its general definition is the same, but manufacturers may assign the letter "E" to a different circuit. The most likely cause changes from one car to another.[1]

Will I pass the MOT with code P2127?

If the code has switched on the engine warning light, no: with that light on, the inspection records a serious defect, and on Euro 5 and Euro 6 cars the ITV (Spain's roadworthiness inspection, similar to the MOT) also reads the OBD diagnostic system. Repair the fault before you go; clearing the code just before the inspection does not help either, because it counts as a serious defect.[4]

Not sure what is wrong with your car? Describe what you notice in the symptom diagnosis or see all fault codes.

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. P2127: Throttle/Pedal Position Sensor/Switch E Circuit LowCarParts.com · Technical documentation · consulted 29 October 2026
  2. OBD DTC Fehlercode P2127CarWiki · Technical documentation · consulted 29 October 2026 · in German
  3. P2127 - Throttle/Pedal Position Sensor/Switch E Circuit Low InputAutoDTCs · Technical documentation · consulted 29 October 2026
  4. Desmontando mitos: ¿puede pasar mi coche la ITV con el testigo de «avería motor» encendido?Diariomotor · Motoring press · published 8 March 2021 · consulted 2 October 2026 · in Spanish