P0120 Code: Meaning, Causes, Symptoms & Fix Cost | AXLY.pro

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)

  1. Failed TPS
  2. Carbon buildup on the throttle plate affecting position learning
  3. Damaged wiring
  4. 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.

Recommended parts & tools for P0120

Compare the parts and tools that pair with AXLY:

Best Throttle Body Cleaners for a Smooth Idle → Browse all car gear →

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Related codes

P0121P0122P0123P0220

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