P2138: Throttle / pedal position sensor correlation (Sensors 1 and 2)
Drive carefully. Get it checked within a week or two.
Can I drive with P2138?
Yes, but drive carefully and get it checked soon. Accelerator gas pedal sensors disagree; car enters reduced power limp mode.
What does P2138 mean?
P2138 stands for Throttle/Pedal Position Sensor/Switch 'D' / 'E' Voltage Correlation.
Symptoms you may notice
- Sudden 'Reduced Engine Power' warning on dashboard
- Gas pedal feels dead or vehicle will not accelerate past 25-30 mph
- Jerky throttle response and abrupt engine surging
How much does it cost to fix?
Repair costs for code P2138 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Failed accelerator pedal sensor assembly
- Moisture or snow melting onto pedal connector
- Pinched wiring under dashboard
- Faulty ECU reference voltage
What to do next
- Check the wiring plug above the gas pedal for moisture or loose fit.
- Cycle ignition off, open driver door, and restart engine.
- Replace the accelerator pedal position assembly (usually 2 or 3 bolts).
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P2138 involves the accelerator pedal assembly on your vehicle's floorboard. When water from wet winter boots drips onto the pedal sensor harness, voltage correlation drops out, putting the car into limp mode. Drying the plug or swapping the pedal fixes it.