Audi A4 Engine Computers

The engine computer, also known as the engine control unit, is a very important part of your Audi A4. The computer receives information from the different systems in the Audi A4 and delivers engine power. Your engine computer must be working properly to ensure that your A4 car runs smoothly.

What is an Audi A4 engine computer?

An Audi A4 computer reads the vehicles sensors and adjusts the engine actuators for optimal performance. Your Audi A4 will also have a transmission computer that controls automatic transmissions. This is true for manual and automatic Audis. The computer has control over many of the A4 cars mechanisms including some of the systems listed below.

  • Air/Fuel Ratio: The computer determines how much fuel to send to the cylinders based on readings. The readings indicate if the air to fuel ratio is off. It also senses the position of the throttle plate and the engine temperature.
  • Valve Timing: The computer controls when valves open. They will open sooner if you are driving at high speeds and increase airflow into the cylinder.
  • Idle Speed: The crankshaft position sensor monitors the RPM, which is an important component in timing other mechanisms such as the fuel injection and spark events. Idle speed control anticipates the engine load when the car is idling.
  • Electronic Valve Control: Some Audi control units have complete control over the opening and closing of the valves as well as the location of the opening. This can lead to more fuel efficiency.
How often should you replace your engine control computer?

It is possible for an Audi control unit to need replacement, but it is unusual. Most A4 computers will last for up to 125,000 miles. If there is a car control unit problem with your Audi, you will not be able to drive your car as many common car operations will not be working properly. The Audis engine light might illuminate on the front dashboard of the car. However, there can be more severe symptoms of a malfunctioning A4 control unit. The car may shut off randomly or not turn on at all. This is a dangerous situation, and you should stop driving your Audi A4 and get the car towed immediately if this happens.

If you suspect that your Audi A4 control unit is not working, you can test it by comparing the actual readings of your car to what they are supposed to be for that particular Audi mechanism. There are many systems at work in the engine control computer, so it can be difficult to diagnose exactly what is wrong with the control unit of the car.

What is a programmable control unit?

Your Audi may have a programmable control unit if you have made modifications to the car. For example, if you add a turbocharger to your Audi, you may need a programmable computer. This is because the control unit does not recognize the changes made to the Audi by the turbocharger. Changing the Audi exhaust system can also affect the control unit.