P08C5Pressure Control Solenoid M Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- GM uses this code on the Corvette's Tremec dual clutch when synchronizer actuation valve 1, serving the odd-gear shaft, keeps pressure on although it is commanded off. The check runs whenever the selector pilot valve changes position: a valve stuck on keeps pushing a shift rod, so after the switch the pressure is routed elsewhere. If within 200 ms one rod moves unintentionally by 1000 µm or more while another relaxes by 125 µm or more, and both position sensors are electrically fine, the fault is set. Type A, monitored continuously. Bulletins 21-NA-033 and 23-NA-197 list it with the other valve codes; debris in the control valve body is the main cause. P08C4 is the stuck off counterpart.
- What you may notice
- Check engine light on
- Clunks or unwanted gear engagement on the odd shaft
- Noise from the transmission area
- Likely causes
- LikelyValve held open by debris in the control valve body
- PossibleDebris from a dislodged snap ring in the direct clutch assembly (bulletin 23-NA-197)
- RareWorn valve bore in the control valve body
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.