P088DReverse Inhibit Control Circuit High
- Generic OBD-II code · Powertrain
- How the car detects it
- The reverse inhibit solenoid on GM's six-speed manual gearboxes (Corvette, Camaro, CTS-V, ATS-V) blocks reverse while driving forward and is released by the engine module. A low-side driver with built-in diagnosis watches the control line: above 9 V and 250 rpm, 20 faults in 25 samples of 250 ms (about 6 s) set the code. GM rates it type C without MIL; from 2019 a service message appears. P0801 is the open circuit. P088D means the control line is shorted to voltage: when the driver switches on it sees too high a level or overcurrent, and the solenoid can no longer be operated, so reverse may stay locked.
- What you may notice
- Reverse cannot be engaged (lockout not released) or is not blocked
- Service message (GM from 2019), no MIL
- Likely causes
- LikelyControl wire shorted to a supply wire in the harness
- PossibleSolenoid coil low-resistance or shorted (driver overcurrent)
- PossibleMoisture or corrosion between supply and control pin
- RareEngine module driver faulty
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.