OBD-II code · Powertrain (generic)
P0120 Throttle Position Sensor / Switch A Circuit Malfunction
The ECU detects a general electrical fault on the throttle position sensor/switch A circuit. Signal missing, implausible, or wiring broken. Generic catch-all when no more specific TPS-A code applies.
Is it safe to drive with P0120?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyTPS worn or failed (dead spot in resistive track)
- PossibleTPS wiring or connector fault
- Less likelyTPS mechanically misaligned to throttle shaft
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Throttle Position Sensor, Tps Wiring, Tps Connector, Throttle Body
Related codes
- P011DCharge Air Cooler Temperature/Intake Air Temperature Correlation Bank 2
- P011EEngine Coolant Temperature 1 / Ambient Air Temperature Correlation
- P011FEngine Coolant Temperature 2 / Ambient Air Temperature Correlation
- P0121Throttle/Pedal Position Sensor "A" Range/Performance
- P0122Throttle/Pedal Position Sensor "A" Low Input
- P0123Throttle/Pedal Position Sensor "A" High Input
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.