P0971: Pressure Control Solenoid C Control Circuit High

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.

Medium severity. Can I keep driving?Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.

Symptoms

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

Most 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

What to check, in order

Start with the simplest. You can tick off each step.

Check the fluid level and condition according to the manufacturer
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the transmission connector
Read the data with a transmission-compatible scanner
Measure the solenoid valve circuit
Leave opening the transmission to a specialized repair shop

Good to know

Repair difficulty: hard
It can trigger limp mode.
It affects emissions.

What each character of P0971 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
9: Transmission
71: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0971?

Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.

What causes code P0971?

The most common causes are: open coil or poor connection (reported as high on GM six-speeds); control wire shorted to a supply voltage; damaged or loose transmission connector.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.