P0920 Gear Shift Forward Actuator Circuit/Open

P0920 indicates a gear shift forward actuator circuit or open-circuit fault. The electrical path for forward gear actuator movement is incomplete.

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 command the actuator repeatedly until the open circuit and load path are checked.

Symptoms of P0920

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 P0920

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 feed, ground, driver command, resistance, current draw, connector fit, and circuit continuity under load.
Inspect actuator wiring, module connector pins, transmission connector sealing, harness routing, and signs of water or fluid intrusion.
Compare forward actuator command with gear position feedback to confirm whether the fault is electrical or mechanical.

Related OBD-II codes

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