OBD Guide

P1812

Transmission Fluid Overtemperature

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$17–89 (est.)

Symptoms

  • Burnt transmission fluid smell
  • Difficulty shifting gears
  • Dips or jerks when switching
  • Reduced engine power
  • Activation of emergency operation mode of automatic transmission

Causes

  • Low transmission fluid level
  • Contaminated or used ATF
  • Malfunction of the automatic transmission cooling radiator
  • Problems with the cooling system thermostat
  • Excessive load on the transmission (towing, aggressive driving)

How to Fix

  1. Check the level and condition of the transmission fluid
  2. Replace ATF fluid and filter if necessary
  3. Check the operation of the transmission cooling system
  4. Diagnose the automatic transmission cooling radiator for blockages
  5. Check the operation of the engine thermostat

Related codes

Error P1812 by Vehicle Brand