The power train control module:
diagnosing transmission errors

The power train control module, also called the PCM, is the main system inside your vehicle that detects and diagnoses errors in the engine control system that cause power train or transmission breakdowns. The PCM houses the TCU (Transmission Control Unit) and the ECU (Engine Control Unit).

The Transmission Control Unit or TCU sends codes that help diagnose problems within the vehicle’s transmission as it works with the Power control module to detect problems. The Transmission Control Unit uses sensors throughout the automobile and transmission in conjunction with the Engine Control Unit or ECU which calculates the functions of the gears in the transmission and can diagnose what is failing inside the transmission.

When we diagnose your car or truck at our Stuart Transmission Repair Shop in Martin County, we check the TCU for any codes that have been stored in its system to help in the diagnostics procedure. This is one of the steps we use to pinpoint the exact problems that are causing your transmission to malfunction.

This is much different than in the past where old cars used hydromechanical controls instead of electronic transmission controls utilizing solenoids.