P0122 — Throttle Position Sensor/Switch A Circuit Low Input
Drive with caution — fix soon.
What P0122 means
This code means the computer is reading an abnormally low voltage signal from throttle position sensor A, which tells the engine how far the throttle is open. It usually points to a faulty throttle position sensor, a wiring or connector problem, or sometimes an issue inside the throttle body. The fix is often as simple as repairing a connector or replacing the sensor, and it's a common, repairable problem.
Common symptoms
- Check engine light is on
- Engine hesitates or stumbles when accelerating
- Car may stall or idle roughly
- Reduced engine power or limp mode
- Unexpected surging or jerking while driving
Common causes
- Faulty throttle position sensor
- Damaged or corroded wiring or connector
- Short to ground in the sensor circuit
- Poor electrical ground or low reference voltage
- Worn or dirty throttle body
Typical repair cost
$100 – $400
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0122 code?
For short trips, usually yes, but you shouldn't rely on it. The car may hesitate, stall, or enter reduced-power mode, so it's best to head to a shop soon rather than take long or highway drives.
How much does it cost to fix a P0122?
Most repairs run from about $100 to $400. A simple wiring or connector fix is on the low end, while replacing the throttle position sensor or throttle body costs more, depending on your vehicle.
Is a P0122 code serious?
It's moderately serious. It won't usually leave you stranded right away, but the erratic throttle response and possible stalling make it something to fix promptly for safety and drivability.
What's the difference between P0122 and P0123?
P0122 means the throttle sensor signal is too low (often a short to ground or open circuit), while P0123 means the signal is too high. Both involve the same sensor but point to opposite electrical faults.