OBDII - Articles - What is PCM?

What is PCM?

- Last Edited: Aug 27, 2023
- Popularity: 5,421 Views


PCM stands for Powertrain Control Module. It is a computer that controls the engine, transmission, and other powertrain components. The PCM receives input from sensors throughout the vehicle, and it uses this information to make decisions about how to operate the powertrain. For example, the PCM can adjust the fuel mixture, spark timing, and transmission shift points to optimize performance and emissions.

The PCM is a critical component in modern vehicles, and it is essential for ensuring the safe and efficient operation of the powertrain. If the PCM fails, it can cause a variety of problems, including engine misfires, poor fuel economy, and emission problems.

Here are some of the functions of the PCM:

      • Injecting the correct amount of fuel into the engine cylinders.
      • Sparking the spark plugs at the correct time.
      • Controlling the air-fuel ratio.
      • Adjusting the transmission shift points.
      • Monitoring engine performance and emissions.
      • Storing diagnostic trouble codes (DTCs).

The PCM is a complex and sophisticated computer, and it is essential for the safe and efficient operation of modern vehicles. If you have any concerns about the PCM in your vehicle, it is important to have it diagnosed by a qualified mechanic.

Here are some of the signs that your PCM may be failing:

      • Engine misfires.
      • Poor fuel economy.
      • Emission problems.
      • The check engine light is on.
      • The vehicle is not starting.

If you notice any of these signs, it is important to have your PCM diagnosed by a qualified mechanic as soon as possible.