P08CB code meaning
Pressure Control Solenoid M Control Circuit High
Powertrain system Generic code P08xx codes Check engine light
What P08CB means
GM uses this code on the Corvette's Tremec dual clutch for synchronizer actuation valve 1 (odd-gear shaft) in two situations. First, a short to battery voltage: with the low-side driver on, a sense voltage above 0.7, 0.9 or 1.1 V (±0.1 V), depending on supply voltage, counts as a shorted load, confirmed after 150 ms. Second, a short to a neighbouring output: at shutdown every output is switched on in turn, a cross-reaction is stored in memory and the code is set at the next start. Type A, MIL at once. The check pauses while P0882 or P0883 is present. A valve shorted to power cannot be switched off, so the transmission will usually go into a fallback mode.
P08CB at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P08CB
- Check engine light on immediately
- Fallback mode with restricted gears
- Code may appear right after starting
Common causes of P08CB
- Most likelyControl wire shorted to battery voltage
- PossibleShort to an adjacent solenoid wire in the internal harness
- Less likelyDefective driver stage in the transmission control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid mWiring harness
What each part of P08CB 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. |
| CB | The exact fault in that area. |
What to do next
- Note P08CB 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 P08CB
What does P08CB mean?
P08CB means "Pressure Control Solenoid M Control Circuit High". GM uses this code on the Corvette's Tremec dual clutch for synchronizer actuation valve 1 (odd-gear shaft) in two situations. It is a generic code, so it means the same on every make.
Is it safe to drive with P08CB?
Drive gently and only to a workshop. With P08CB the car can go into limp mode (reduced power) to protect itself.
Will P08CB fail an emissions test?
Yes, it can. P08CB 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 P08CB to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P08CB clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.