The Autocheck Computer

Introduction | Functionality | Hidden Features | Country Coding | Fuel/Range Calibration  

Hidden Features

This section outlines the functional checks that can be performed on the Autocheck computer by a simple procedure. This can be used to verify the correct computer and country specific code plug is fitted to your car. In addition it can determine some faults in the connection between the ECU and the Autocheck module with respect to the fuel consumption signal.

The procedure to access these hidden codes from the Autocheck computer is as follows:

With the ignition key in the OFF position, press and hold down the Autocheck RESET button.
Keeping the RESET button pressed, turn the ignition key to the ON position. Verify that the correct Autocheck computer code is displayed (a532 - also shared with the 20V non turbo quattro).
Release the RESET button and verify that the next number displayed is approximately the amount of fuel in the tank. This is displayed in litres x 10 (e.g 30 litres in the tank is display as 300).
Press and hold the Autocheck UP button and verify that the correct country code is displayed (eg GB, EU, SA or AU). This is determined by the coding plug and establishes if fuel & range calculations are performed in gallons, litres, miles or kilometres.
Release the UP button , then press and hold the Autocheck DOWN button and verify that the appropriate range calibration adjustment is displayed. This was set to zero in the factory, but can be adjusted by a special procedure to +/- 15% if it is necessary to recalibrate the range parameters.

Note that you may encounter an 'aF' code at this step if the fuel usage signal from the ECU is not detected by the Autocheck / Trip computer. More details to follow as and when I get it...


Last Updated 27th September 2002