P0781 — Transmission shift 1–2 malfunction

P0781: Transmission shift 1–2 malfunction — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

The controller reports a problem completing the 1–2 gear transition. This concerns shift execution rather than necessarily a defective shift switch or one named solenoid. The commanded transition and the achieved ratio must be distinguished.

Affected system: Transmission shift execution

Symptoms

  • Delayed/jerky 1–2 shift; prolonged first-gear operation.

Possible causes

  • Faulty solenoids, worn friction elements or low/contaminated ATF.

What to check

  • Check ATF, TCM codes and connections; request transmission-pressure testing.

Also written as: P0781-00, P078100, PO781 (some scan tools add the fault-type byte, e.g. -00).