P2135: Throttle position sensor correlation error (Sensors 1 and 2)
Drive carefully. Get it checked within a week or two.
Can I drive with P2135?
Yes, but drive carefully and get it checked soon. Throttle position sensors disagree; vehicle is in reduced engine power (limp mode).
What does P2135 mean?
P2135 stands for Throttle/Pedal Position Sensor/Switch 'A' / 'B' 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 P2135 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:
- Worn electronic throttle body assembly
- Corroded throttle body wiring pigtail
- Carbon buildup binding throttle plate
- Defective accelerator pedal sensor
What to do next
- Pull over and cycle ignition off for 2 minutes to temporarily reset limp mode.
- Inspect the wiring plug at the throttle body for loose terminal tension.
- Replace the electronic throttle body assembly and pigtail.
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 P2135 is notorious on GM, Ford, and Nissan vehicles. The computer reads two conflicting voltages from the dual throttle sensors and enters 'Reduced Engine Power' mode (max 25-30 mph) for runaway prevention. Replacing the throttle body or pigtail cures it.