P2AD2 code meaning
Throttle/Pedal Position Sensor/Switch B/G Voltage Correlation
Powertrain system Generic code P2Axx codes Check engine light
What P2AD2 means
P2AD2 sets when signals B and G no longer agree in voltage. On engines with one throttle body per bank this is a cross-bank comparison: with GM's 2023 letter scheme, B is the second track of the bank 1 throttle and G the second track of the bank 2 throttle. Mercedes-Benz uses P2AD2 on its M177 twin-turbo V8 (AMG C63, E63, GLE63, GT63, also GLE/GLS 580 and Maybach GLS 600): the third version (August 2026) of bulletin LI07.10-P-080384 added P2AD200 to its list and traces it, together with P2135, P2136 and P2AD3, to high resistance in the pins of both throttle actuators, left and right; the fix is new silver- and gold-plated terminals and seals. Drivers notice the check engine light and possibly reduced power.
P2AD2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2AD2
- Check engine light on
- Possible loss of power
- Further throttle codes such as P2135 or P2136 stored
Common causes of P2AD2
- Most likelyHigh resistance at the pins of the throttle actuator connectors
- PossibleDrifting position track in one of the throttle bodies
- Less likelyDamaged wiring to one throttle actuator
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Throttle position sensor bThrottle position sensor gECM
What each part of P2AD2 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. |
| D2 | The exact fault in that area. |
What to do next
- Note P2AD2 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 P2AD2
What does P2AD2 mean?
P2AD2 means "Throttle/Pedal Position Sensor/Switch B/G Voltage Correlation". P2AD2 sets when signals B and G no longer agree in voltage. It is a generic code, so it means the same on every make.
Is it safe to drive with P2AD2?
Drive gently and only to a workshop. With P2AD2 the car can go into limp mode (reduced power) to protect itself.
Will P2AD2 fail an emissions test?
Yes, it can. P2AD2 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 P2AD2 to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P2AD2 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.