P08C5 code meaning
Pressure Control Solenoid M Stuck On
Powertrain system Generic code P08xx codes Check engine light
What P08C5 means
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.
P08C5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P08C5
- Check engine light on
- Clunks or unwanted gear engagement on the odd shaft
- Noise from the transmission area
Common causes of P08C5
- Most 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)
- Less likelyWorn valve bore in the control valve body
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid mValve body
What each part of P08C5 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8 | Area: transmission. |
| C5 | The exact fault in that area. |
What to do next
- Note P08C5 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 P08C5
What does P08C5 mean?
P08C5 means "Pressure Control Solenoid M Stuck On". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P08C5?
Drive gently and only to a workshop. With P08C5 the car can go into limp mode (reduced power) to protect itself.
Will P08C5 fail an emissions test?
Yes, it can. P08C5 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 P08C5 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P08C5 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.