P0923 Gear Shift Forward Actuator Circuit High

P0923 points to a high gear shift forward actuator circuit. The actuator 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 perform adaptation or calibration until the high actuator circuit is corrected.

Symptoms of P0923

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 P0923

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 forward actuator circuit voltage, continuity, ground, connector fit, open circuits, short-to-voltage faults, and driver state.
Inspect transmission connector terminals, actuator connector sealing, harness damage, and wiring disturbed during clutch or gearbox service.
Compare command and position feedback to determine whether the actuator is disconnected, electrically stuck high, or mechanically blocked.

Related OBD-II codes

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