Audi Workshop Service and Repair Manuals

• ‒ Switch ignition off.
• ‒ → Remove cover for diagnosis plug (only in vehicles up to model year 2000).
• ‒ Connect fault reader V.A.G 1551 using cable V.A.G 1551/3.

Notes:

• ◆ The illustration shows the arrangement of the diagnosis plug in vehicles up to model year 2000. In vehicles as of model year 2001 the diagnosis plug is located near the "right-hand A-pillar" in the cover underneath the dash panel.
• ◆ Alternatively the vehicle diagnosis, measuring and information system VAS 5051 can be connected with the diagnosis wire VAS 5051/1 or the vehicle system tester V.A.G 1552 with diagnosis wire V.A.G 1551/3.
• ◆ If testers and measuring equipment have to be used during a test drive, observe safety precautions

• ◆ The following describes self-diagnosis using the fault reader V.A.G 1551 only.
• ◆ When using vehicle diagnosis, measurement and information system VAS 5051, or the vehicle system tester V.A.G 1552, follow the procedures described in the appropriate operating instructions.

Notes:

• ◆ If nothing is displayed on the fault reader V.A.G 1551, check wiring for diagnostic connector according to current flow diagram.

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations

• ◆ Depending on the program, additional operating instructions can be printed out by pressing the HELP key on V.A.G 1551.
• ◆ Use the ⇒key to continue through the program.
• ◆ The PRINT key switches on the printer (lamp in the key lights up).
• ◆ The fault memory cannot be erased until it has been interrogated.

• ‒ Switch on ignition/start engine.
• ‒ Switch on compressor (press "Auto" button of operating and display unit -E87).
• ‒ Press key -1- to select "Rapid data transfer" mode.

Note:

To check the vehicle speed signal (in the "Reading measured value block" function), move vehicle a few metres at walking pace before entering into self-diagnosis mode.

• ‒ Press keys -0- and -8- (08 enters address word for testing the vehicle's "electronic climate/heating control").

• ‒ Press Q to confirm entry.

Control unit identification (example)

Notes:

• ◆ Depending on the coding, the displayed vehicle type is A3 or A4 (up to index "E"). A4 is always displayed for newly installed operating and display units that have not yet been encoded .
• ◆ For vehicles with map-controlled cooling (for 1.6 l engine to be gradually introduced as from model year 1999):

• ‒ The codes for the operating and display unit -E87 are different to those for vehicles without map-controlled cooling.
• ‒ A centre vent temperature sender -G191 is also installed (in air duct for "centre" dash panel vent).
• ‒ The -E87 must be adjusted to the other set-up for the engine cooling via a different code (the refrigerant temperature is controlled by the engine control unit according to the engine load and is higher when the engine is running at part throttle in comparison to full throttle).

• ◆ As of model year 2000, the assignment of the ignition key is conveyed by the dash panel insert (data telegram) together with the refrigerant temperature (when ignition is switched on). This information can only be processed by operating and display unit -E87 with part number 8L0 820 043 as of index "H". As the indices "H", "J", "K" and "L" are already allocated to a modified version of -E87 (use in series production for model years 2001), operating and display units with part number 8L0 820 043 and indices "M" (or "N" for Japan) will be installed until production has been reorganised.

=> Electrical System; Repair group 01

=> Parts List

• ◆ Control unit identification 8L0 820 043 X A3 or A4 Fully automatic air conditioner (depending on the code, assignment=> Parts List).

=> Parts List

• ◆ Coding XXXXX
• ◆ WSC ZZZZZ is the workshop code for V.A.G 1551 that was used to perform the previous encoding.
• ◆ DXX designates the software version of operating and display unit -E87 and has no relevance for customer service.

Only the functions listed above can be used for the self-diagnosis of the electronic climate/heating control.

• ‒ Press ⇒key.

Notes:

• ◆ Pressing the HELP key prints a list of possible functions.
• ◆ Pressing the ⇒ key returns V.A.G 1551 program to its initial setting.
• ◆ If one of the following fault messages appears on the display:

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations

• ‒ After eliminating the possible causes of trouble, enter address word 08 again for "Electronic climate/heating control" and confirm with Q key.

• ‒ Press ⇒key.