P0931 Gear Shift Lock Solenoid Control Circuit High

P0931 points to a high gear shift lock solenoid control circuit. The solenoid control path is open, shorted to voltage, or above expected range.

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 replace brake switch parts until the high shift-lock solenoid circuit is isolated.

Symptoms of P0931

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 P0931

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 shift-lock solenoid signal voltage, ground, continuity, open circuits, short-to-voltage faults, connector fit, and driver state.
Inspect shifter connector pins, console harness routing, spilled-liquid damage, solenoid resistance, and related brake switch inputs.
Verify whether the high circuit prevents shifter release, causes intermittent release, or appears only with the pedal pressed.

Related OBD-II codes

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