P0971 Pressure Control Solenoid C Control Circuit High

P0971 indicates a high pressure control solenoid C control circuit signal. The solenoid control path is higher than expected or stuck high.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not condemn the controller before checking pressure solenoid C wiring and connector integrity.

Symptoms of P0971

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0971

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Check for short-to-voltage, open ground, poor connector contact, and pressure solenoid C control circuit faults.
Compare solenoid command with circuit voltage or current and pressure behavior during shifts.
Inspect transmission connector sealing, internal harness routing, and recent wiring repairs.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.