P2AD1Throttle/Pedal Position Sensor/Switch C/G Voltage Correlation
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2AD1 compares the voltages of position signals C and G and sets when they stop describing the same position. What the letters mean depends on the layout; GM's 2023 table 23OBDG07 for an engine with two throttle bodies is the clearest public key: C is sensor 1 and G sensor 2 of the bank 2 throttle (P0227/P0228 and P212C/P212D), so C/G is the internal pair of that second throttle, the counterpart of the bank 1 pair A/B under P2135. GM's table itself checks each track against modelled air charge rather than listing P2AD1, and no maker documents the code publicly. Typical causes are a worn track in the bank 2 throttle, contact resistance in its connector or a shared ground or reference fault. The ECU then usually limits throttle opening.
- What you may notice
- Check engine light on
- Reduced power or limited throttle response
- Likely causes
- LikelyRaised contact resistance in the throttle connector
- PossibleWorn or drifting sensor track in the second throttle body
- RareFault on the shared 5 V reference or sensor ground
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.