Wiring harness damage (chafed, corroded, or broken wires) between the sensor and the engine control module (ECM); Faulty throttle position sensor or accelerator pedal position sensor 'E'; Poor electrical connection at the sensor or ECM connector; Internal ECM fault, though less common; Water or debris intrusion into the sensor connector; Aftermarket or improperly installed electronic throttle control components

DTC codes / P21xx · Fuel and air metering / P2125

P2125Throttle/Pedal Position Sensor/Switch 'E' Circuit

Q: What does code P2125 mean?

Throttle/Pedal Position Sensor/Switch 'E' Circuit. P2125 indicates a fault in the electrical circuit for throttle or pedal position sensor 'E', which is a redundant sensor used by the engine computer to verify driver demand. The computer compares sensor 'E' against other throttle or pedal sensors and sets this code when the signal is out of range, intermittent, or implausible.

P2125 indicates a fault in the electrical circuit for throttle or pedal position sensor 'E', which is a redundant sensor used by the engine computer to verify driver demand. The computer compares sensor 'E' against other throttle or pedal sensors and sets this code when the signal is out of range, intermittent, or implausible.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode, limiting acceleration
Hesitation or stumble when pressing the accelerator pedal
Unresponsive or delayed throttle response
Poor fuel economy or erratic idle in some cases

Common causes, most likely first

Wiring harness damage (chafed, corroded, or broken wires) between the sensor and the engine control module (ECM)
Faulty throttle position sensor or accelerator pedal position sensor 'E'
Poor electrical connection at the sensor or ECM connector
Internal ECM fault, though less common
Water or debris intrusion into the sensor connector
Aftermarket or improperly installed electronic throttle control components

How to diagnose and fix it

Inspect the sensor connector and wiring for corrosion, damage, or loose pins
Check for technical service bulletins (TSBs) related to the throttle or pedal sensor circuit
Measure sensor reference voltage and ground at the sensor connector
Perform a wiggle test on the harness while monitoring sensor data to detect intermittent faults
Compare sensor 'E' readings with other throttle/pedal sensors using a scan tool to check for plausibility
Replace the faulty sensor if wiring and connections are good
Reprogram or replace the ECM only after all other causes are ruled out

Don't overlook the wiring harness

A common oversight is replacing the throttle body or pedal assembly without first checking the wiring harness for chafing or corrosion, which often causes intermittent P2125.
The code can be set by a weak battery or charging system issue that causes low voltage to the sensors, so always verify battery health before condemning parts.
On some vehicles, P2125 may be stored alongside other throttle codes like P2135 or P2138, indicating a correlation issue rather than a single sensor failure.
Aftermarket throttle controllers or pedal tuners can interfere with sensor signals and trigger P2125, so check for any modifications.
A relearn procedure for the electronic throttle system may be required after repairs, and skipping it can cause the code to return.

Can I keep driving with P2125?

If the vehicle is in limp mode or has severely reduced power, avoid driving and seek service immediately. If the check engine light is on but the car drives normally, you can drive cautiously to a repair shop, but avoid aggressive acceleration or heavy loads.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.