Powertrain, generic · Transmission

P0968 Pressure Control Solenoid C Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Open circuit in the driver of pressure control solenoid C. GM's 8-speed assigns C to clutch 3 (C13567), the 9-speed to CB38 and the 10-speed to C23457910; an impedance above 200 kOhm for 0.3 s counts as open and sets a Type A code after one trip. In GM's dual-clutch gearbox, C is the redundant shutdown valve of the odd clutch, checked for open load while its output is switched off and confirmed after 150 ms. GM six-speeds report an open C solenoid as P0971, and neither Ford's summaries nor the Allison 1000 tables list C codes. CARB requires circuit checks on transmission output components. Low and high are P0970/P0971, performance P0969; the usual result is a lost gear range or limp mode.

Likely causes

Open solenoid coil
Poor contact at the transmission connector or internal harness
Broken control wire
Faulty output stage in the control module

Symptoms

  • MIL and transmission warning on
  • Gears that need clutch C are unavailable
  • Limp mode in a fixed gear

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,800
Time1–5 h

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

Parts involved

pressure control solenoid cwiring harnesstcm

Related codes

P0969P0970P0971P0960P0964P0795

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