Powertrain, generic · Transmission

P0971 Pressure Control Solenoid C Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Pressure control solenoid C circuit high: a short to voltage, and on GM six-speeds also an open, as there is no separate open code there. The Saab 9-4X 6T70 (clutch pressure solenoid 3, low/reverse and 4-5-6 clutches) and GM's 2018 six-speed table set it after 1 s or 0.3 s as Type A, with limp mode in reverse and 5th gear at maximum line pressure. GM's 8-, 9- and 10-speeds use the code for their clutch solenoid C; GM's dual-clutch gearbox for the redundant odd-clutch shutdown valve, where too high a voltage at the sense pin with the output switched on counts as a short. Ford does not use C codes. Siblings: P0968 open, P0970 low, P0969 performance. A loose connector can make the fault come and go.

Likely causes

Open coil or poor connection (reported as high on GM six-speeds)
Control wire shorted to a supply voltage
Damaged or loose transmission connector
Faulty output stage in the control module

Symptoms

  • MIL on, limp mode in a fixed gear
  • Harsh engagements at maximum line pressure
  • Fault comes and goes with temperature or vibration

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

P0968P0969P0970P0963P0967P0798

References: saabwisonline.com, gsi.ext.gm.com, gsi.ext.gm.com.