MotorBitP0122: Throttle/Pedal Position Sensor/Switch A Circuit Low
Throttle position signal is too low. Drive-by-wire cars may go into limp mode.
Educational OBD2 information. Confirm on your vehicle with a scan tool. MotorBit can read this code, freeze frame, and live data over an ELM327 adapter.
What P0122 means
TPS/APP circuit voltage is below the valid range.
Why the check engine light comes on
The PCM cannot trust throttle request, so it lights the MIL and may limit power.
Common causes
- Failed TPS
- Wiring short to ground
- Dirty throttle body
- Pedal sensor fault
Typical symptoms
- Limp mode
- No throttle response
- High idle or stall
What to do next
- Watch TPS % in MotorBit — it should move smoothly from ~0–100.
- Inspect the connector at the throttle body.
- Clean carbon from the throttle plate if it sticks.
How MotorBit helps
Open MotorBit, connect your ELM327, and read P0122 with freeze frame (RPM, load, temperature, speed at the moment the fault set). Then watch live PIDs and fuel trims instead of replacing parts by guesswork. When the repair is verified, clear the code and re-check monitors.
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FAQ
Is P0122 serious?
Severity is listed as high on this page. Misfire, crank/cam, and communication codes deserve faster attention than a tiny EVAP leak.
Will disconnecting the battery clear P0122?
It may hide the lamp temporarily, but the fault usually returns and you lose freeze-frame evidence. Scan first, then clear after the repair.
Can MotorBit clear P0122?
Yes, after you understand the cause. Clearing without a repair is how the light comes back on the next drive cycle.