P0634 OBD II Trouble Code PCM/ECM/TCM Internal Temperature Too High

How to easily troubleshoot and repair, and causes of a P0634 trouble code which indicates too high of temperature reading of the internal temperature inside a PCM, ECM, or TCM module.

Symptoms of P0634 OBD II Trouble Code

  • Engine will not start
  • Engine may stall
  • Improper shifting
  • Transmission warning lamp illuminated
  • Check engine light illuminated

Common Causes of P0634 OBD II Trouble Code

  • Corroded or damaged connector
  • Loose or defective control module ground strap
  • Faulty or damaged wiring
  • Defective PCM, ECM, or TCM

Severity of P0634 OBD II Trouble Code

The severity of this code can vary tremendously from just an illuminated check engine light or a transmission warning lamp on a vehicle that starts and runs to an automobile that will stall or not start at all. The code can be serious depending on the specific nature of the problem.