The engine control unit is located in the protective housing in the engine compartment on the left hand side.

- Switch off the ignition

- Remove the cover of the control unit protective housing.

- Undo the connector clips and disconnect the connectors from the engine control unit.

- Take out the old engine control unit and insert the new one.

Engine control unit coding table (AMX)

The code is composed as follows:

                              Country / Emissions standard

0 4 X X X               : Rest of the World, Japan, Mexico

0 8 X X X               : China

1 1 X X X               : EU4

2 6 X X X               : Steam pressure critical countries

2 7 X X X               : Brazil

                              Drive train / Auxiliary functions

     0 X X                : Front-wheel drive without traction control (ASR)

                                Front-wheel drive without Electronic Stability Programme (ESP)

     2 X X                : Four-wheel drive without Electronic Stability Programme (ESP)

     5 X X                : Front-wheel drive with traction control (ASR)

                                Front-wheel drive with Electronic Stability Programme (ESP)

     7 X X                : Four-wheel drive with Electronic Stability Programme (ESP)

                              Note:

                              Vehicles with "ASR" or with "ESP" have a pressure switch in the centre console labelled "ASR" or "ESP".

                              Gearbox

        0 X                 : 5-speed manual gearbox

        5 X                 : Automatic gearbox 01V (5HP19)

        8 X                 : Direct-shift transmission 01J (VL30)

                              Model

           1                 : Audi A4

           2                 : Audi A6

           3                 : Audi A8

Coding example: 

1 1 7 0 1                 : EUIV, four-wheel drive with ESP, 5-speed manual gearbox, Audi A4