OBD-II code · Powertrain (generic)

P081D Neutral Input Circuit

General electrical fault on the Neutral input circuit — used by ECM/PCM to detect Neutral and adjust idle speed and start enable.

Is it safe to drive with P081D?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyOpen or shorted neutral input wire

Symptoms

  • Check engine or transmission warning light on
  • Harsh, delayed, or missing shifts
  • Possible limp mode (locked in one gear)
  • Slipping or shuddering during gear changes

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Usually unaffected
Parts involved
Neutral Input Circuit, Wiring Harness

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.