P0918 Gear Shift Position Circuit Intermittent

P0918 indicates an intermittent gear shift position circuit fault. The gear position signal drops out or becomes invalid only sometimes.

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 clear intermittent position codes without reproducing the signal loss under realistic conditions.

Symptoms of P0918

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 P0918

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

Graph gear position data during gear selection, road vibration, hot operation, and harness movement around the actuator or shifter.
Inspect terminal tension, connector locking, wire flex points, sensor mounting, shared reference stability, and fluid or water intrusion.
Check whether the intermittent fault coincides with missed shifts, wrong gear indication, shift aborts, or adaptation failures.

Related OBD-II codes

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