What does code P0122 mean on a Mercedes-Benz and is it safe to drive?
P0122: Throttle/Pedal Position Sensor A Circuit Low Input. Here's what it means on your Mercedes-Benz, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
PowertrainMedium urgency
What this code means
The throttle position sensor (TPS) is reporting a voltage below the minimum expected range. The PCM relies on TPS data to manage fuel delivery and transmission shift points. A low signal can cause erratic throttle response or limp mode.
Common causes for your Mercedes-Benz
- Failed throttle position sensor
- Damaged or corroded TPS wiring or connector
- Faulty throttle body
- PCM failure (rare)
Symptoms
- Check Engine Light
- Hesitation or stumble on acceleration
- Engine may enter limp mode
- Erratic idle
Typical fixes
- Replace throttle position sensor
- Clean throttle body and inspect TPS connector
- Repair damaged wiring
Repair cost range
For a Mercedes-Benz, repairs for P0122 often fall between $100 and $350, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.