Powertrain, generic · Transmission

P08CA Pressure Control Solenoid M Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

GM sets this code on the Corvette's Tremec dual clutch for a short to ground in the circuit of synchronizer actuation valve 1, which serves the odd-gear shaft. The test runs while the low-side driver is switched on: the sense pin should then sit at a defined level, and if the driver chip reports it below about 1.7 V (±0.5 V), a ground short is assumed. Confirmation takes 150 ms at 8.75 to 18 V battery voltage with the engine not cranking, and the check is suspended when P0882 or P0883 is present. Type A, MIL at once, monitored continuously. Valves 2 to 5 have their own low codes (P27BF onwards). The driver should expect a fallback mode until the wiring fault is repaired.

Likely causes

Control wire chafed through to ground
Shorted turns in the solenoid coil
Fluid in the transmission connector

Symptoms

  • Check engine light on immediately
  • Fallback mode with restricted gears

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time0.5–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pressure control solenoid mwiring harness

Related codes

P08C3P08C8P08C9P08CBP08C1P27BF

References: gsi.ext.gm.com, gsi.ext.gm.com, law.cornell.edu.