An open ground at the sensor. A signal wire shorted to voltage. A failed throttle position sensor.

P0123 Throttle/Pedal Position Sensor/Switch "A" Circuit High

Q: What does P0123 mean?

P0123 means throttle position sensor A's signal is too high, from wiring or a failed sensor, usually with reduced power. The throttle position sensor A signal voltage is too high, usually from an open ground, a short to voltage or a failed sensor.

Throttle

P0123 means throttle position sensor A's signal is too high, from wiring or a failed sensor, usually with reduced power.

The throttle position sensor A signal voltage is too high, usually from an open ground, a short to voltage or a failed sensor.

Can I keep driving? Not if you can avoid it.

Expect reduced power or limp mode, possibly without warning. Get it fixed before relying on the vehicle.

Common causes

An open ground at the sensor
A signal wire shorted to voltage
A failed throttle position sensor

Symptoms

Reduced power or limp mode
High or erratic idle
Check-engine light

What to check first

Check the sensor's ground and connector.
Check the signal voltage at closed throttle against spec.
Look for chafed wires touching other circuits.
Replace the sensor or throttle body if wiring is good.

What does P0123 mean on your vehicle?

The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.

Ask iRepair about P0123

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Related codes

General guidance for P0123 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.