OBD-II code · Powertrain (generic, extended)

P273D Gear Shift Control Module A Supply Voltage High

The gear shift control module A reports a supply voltage above the operating range.

Is it safe to drive with P273D?

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

Common causes

  • Most likelyAlternator regulator failed to limit output
  • Less likelyLoad dump transient after disconnecting a heavy load

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
Best left to a mechanic
Typical labour
1–3.5 h
Emissions test
Usually unaffected
Parts involved
Gear Shift Module A, Charging System

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