Engine sensors
P0122 — Throttle/Pedal Position Sensor/Switch A Circuit Low
The throttle or pedal position sensor A signal is lower than the normal range. The ECU cannot read the driver's throttle request properly and may limit power.
Common causes
- Faulty throttle position sensor
- Open or shorted wire in the signal circuit
- Poor ground or missing 5 V supply
- Corroded connector
- Faulty throttle body
Symptoms
- No or poor response to the accelerator
- Rough idle or stalling
- Limp mode
- Check engine light
How to check
- Check the connector and wiring for opens and shorts
- Measure the 5 V reference, ground and the signal voltage
- Move the throttle slowly and watch the signal on a scan tool
- Replace the sensor or throttle body if the signal drops out
Can you keep driving?
Not recommended in traffic: reduced power or poor throttle response can be dangerous. Have it repaired soon.
Related codes
Frequently asked questions
- What does P0122 mean?
- The sensor A voltage is below its normal range.
- Will the car start with P0122?
- Often yes, but it may idle badly or go into limp mode.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.