Check Engine Code
P0120
Throttle / Pedal Position Sensor A Circuit Malfunction
Severity: high
DIY difficulty: 2/5
Typical cost: $50–$500
What P0120 means
The TPS tells the ECM how far the throttle plate (or pedal, on drive-by-wire) is opened. P0120 means the signal is erratic or stuck. On drive-by-wire cars this can trigger reduced-power mode.
Symptoms
- Check engine light
- Limp mode / reduced engine power
- Hesitation or surging
- Rough idle
- Stalling
Likely causes (most common first)
- Failed TPS
- Carbon buildup on the throttle plate affecting position learning
- Damaged wiring
- Failed throttle body assembly
Can I keep driving?
High — risk of damage if ignored
Typical repair cost
DIY fixes can start near $50 (parts only). Shop repairs for P0120 typically run up to $500 depending on the underlying cause and vehicle. Start with the most common cause — Failed TPS — before throwing parts at it.
Related codes
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