Error code

OBD2 P0120

OBD2P0120
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Throttle/Pedal Position Sensor/Switch 'A' Circuit.

Severity

moderateCan drive, but performance issues may occur.

Summary

P0120 indicates a malfunction in the throttle position sensor (TPS) or accelerator pedal position (APP) sensor circuit 'A'. This code is related to issues with wiring, sensors, and the engine control module (ECM).

Symptoms

  • Hesitation or stumbling upon acceleration
  • Unstable idle
  • Illuminated check engine light

Common Causes

  • Faulty TPS sensor
  • Open or shorted TPS circuit
  • PCM (Powertrain Control Module) malfunction

Diagnosis

  1. Visually inspect the sensor and its wiring for damage or corrosion.
  2. Check the throttle body assembly for binding or contamination.
  3. Test the TPS sensor using a multimeter to check voltage readings at idle and wide open throttle (WOT).
  4. Inspect the TPS circuit wiring for continuity issues.

Fixes

  • Replace faulty TPS sensor if necessary.

FAQ

What should I do if my car has P0120?

Start by visually inspecting the throttle position sensor and its wiring. If no issues are found, test the TPS with a multimeter to check for proper voltage readings.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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