P2AD1 code meaning
Throttle/Pedal Position Sensor/Switch C/G Voltage Correlation
Powertrain system Generic code P2Axx codes Check engine light
What P2AD1 means
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.
P2AD1 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2AD1
- Check engine light on
- Reduced power or limited throttle response
Common causes of P2AD1
- Most likelyRaised contact resistance in the throttle connector
- PossibleWorn or drifting sensor track in the second throttle body
- Less likelyFault on the shared 5 V reference or sensor ground
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Throttle position sensor cThrottle position sensor gECM
What each part of P2AD1 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| D1 | The exact fault in that area. |
What to do next
- Note P2AD1 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2AD1
What does P2AD1 mean?
P2AD1 means "Throttle/Pedal Position Sensor/Switch C/G Voltage Correlation". P2AD1 compares the voltages of position signals C and G and sets when they stop describing the same position. It is a generic code, so it means the same on every make.
Is it safe to drive with P2AD1?
Drive gently and only to a workshop. With P2AD1 the car can go into limp mode (reduced power) to protect itself.
Will P2AD1 fail an emissions test?
Yes, it can. P2AD1 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2AD1 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2AD1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.