P1591 — Subaru — Neutral-position switch: input signal too low

The 2001 Subaru Forester DOHC Turbo manual assigns P1591 to this circuit on automatic-transmission models.

Meaning, symptoms, causes and checks

The 2001 Subaru Forester DOHC Turbo manual assigns P1591 to this circuit on automatic-transmission models. The diagnosis below is limited to that configuration.

Affected system: Transmission-position signal

Symptoms

  • Incorrect idling.

Possible causes

  • A short to ground in the signal path between the ECM and transmission.

What to check

  • Check for P0705 first. Then test the signal and wiring using the exact transmission diagram.