P0929 Gear Shift Lock Solenoid Control Circuit Range/Performance

P0929 points to gear shift lock solenoid control range/performance. The solenoid circuit may operate, but release behavior or feedback is not as expected.

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 the shifter assembly until solenoid command, brake input, and mechanical release movement are compared.

Symptoms of P0929

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 P0929

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

Compare shift-lock command with actual solenoid movement, brake switch status, park position data, battery voltage, and shifter release timing.
Inspect solenoid binding, shifter mechanism drag, spilled-liquid residue, connector voltage drop, and brake switch correlation.
Check whether the issue occurs only cold, after parking, with low voltage, or after console or shifter service.

Related OBD-II codes

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