P0122 Code: Throttle Position Sensor/Switch Circuit Low Input
🟠 Moderate severity · drivable
Drivable, but the throttle reading is too low, which can cause hesitation and poor idle.
What P0122 means
The throttle position sensor (TPS) is reporting voltage that's too low for the throttle's actual position. The computer may think the throttle is closed when it isn't.
Symptoms
- Check engine light is on
- Hesitation on acceleration
- Rough or low idle
- Possible stalling
Common causes
- most common: Faulty throttle position sensor
- common: Shorted or damaged TPS wiring
- less common: Corroded TPS connector
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the throttle position sensor | Yes | $50–150 |
| Repair shorted TPS wiring | Mechanic | $50–150 |
Frequently asked questions
Can I drive with a P0122 code?
Yes, but acceleration may hesitate. Fix it soon.
What is the most common cause of P0122?
A faulty throttle position sensor reading low voltage.
How much does it cost to fix a P0122?
Typically $50–$150 for a new throttle position sensor.
Related codes
P0121
P0121 Code: Throttle Position Sensor/Switch Circuit Range/Performance
P0123P0123 Code: Throttle Position Sensor/Switch Circuit High Input
P0120P0120 Code: Throttle Position Sensor Circuit
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.