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P2123 Throttle Actuator Control
Pedal Position Sensor / Switch D Circuit High Input
P2123 means the accelerator pedal position sensor D circuit read voltage above the expected range, indicating a short to voltage or an open ground in that sensor circuit.
🚗 Not recommended. A high pedal signal can force limp mode.
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🎯 Top Causes, Ranked by Likelihood
#1 Failed accelerator pedal position sensor $100-$400
A shorted-high sensor element reads above range.
#2 Wiring shorted to voltage or open ground $50-$300
A short to power or lost ground raises the signal.
#3 Corroded pedal connector $0-$150
Corrosion can drive the signal high.
#4 Poor ground reference $50-$300
A missing ground pushes the sensor voltage high.
🩺 Common Symptoms Reduced power / limp mode Check engine light Poor throttle response Hesitation Erratic idle 💰 Repair Cost: DIY vs Shop
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🔧 How to Diagnose P2123 1 Read live data for the pedal position sensor circuit
2 Inspect the pedal wiring for shorts to power or open ground
3 Test the sensor ground circuit
4 Replace the pedal position sensor if the signal stays high
❓ Frequently Asked Questions Can I drive with a P2123 code?
Avoid it. A high pedal signal commonly forces limp mode with reduced power.
How much does it cost to fix P2123?
A pedal position sensor replacement typically runs $150-$600 at a shop.
What causes P2123?
Usually a failed pedal sensor, a short to voltage, or an open ground in the circuit.
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