Powertrain, generic · Transmission

P08C7 Pressure Control Solenoid M Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Reports an on-and-off fault of pressure control solenoid M, such as brief circuit dropouts or occasional implausible responses. No manufacturer documents this code publicly; GM, which uses letter M for synchronizer actuation valve 1 of the Corvette dual clutch, lists no intermittent code for it, and earlier packages found the intermittent codes of the other pressure control solenoids unused as well. GM's circuit tests need a fault to last 150 ms, so short dropouts mostly end up as P08C8, P08CA or P08CB once they persist. CARB requires transmission solenoids to be monitored. Loose terminals and chafed wires are the likely causes; symptoms are sporadic shift faults and a warning light that comes and goes.

Likely causes

Loose terminal at the solenoid or transmission connector
Chafed wire with intermittent contact
Debris causing occasional valve hang-ups

Symptoms

  • Warning light that comes and goes
  • Sporadic rough shifts

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

P08C3P08C6P08C8P08BE

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