Audi Workshop Service and Repair Manuals

Faults occurring in monitored sensors or components are stored in fault memory together with an indication of the type of fault.

The first step in the fault-finding process is always to start self-diagnosis and interrogate the faults stored. This can be implemented by way of the following:

• ◆ Vehicle diagnostic, testing and information system VAS 5051
• ◆ Fault reader V.A.G 1551
• ◆ Vehicle system tester V.A.G 1552

The fault information displayed is used in conjunction with a fault table (containing information on possible causes of trouble) to perform pin-pointed repair measures.

Notes on fault indication:

• ◆ If a fault condition exists for longer than a pre-determined period, the fault is stored as being static. If the fault condition is then no longer detected for a pre-determined period, the fault is re-classified as being a sporadic fault. This process is constantly repeated. Sporadic faults are additionally identified as such by /SP on the display.

• ◆ A sporadic fault is erased automatically if it no longer occurs for a pre-determined period.

The possibilities offered by self-diagnosis can only be utilised by way of the vehicle diagnostic, testing and information system VAS 5051, the fault reader V.A.G 1551 or the vehicle system tester V.A.G 1552 in mode 1 "Rapid data transfer".

Self-diagnosis is not restricted to storage, interrogation, cancellation and final control diagnosis. It also offers basic setting, control unit identification and encoding functions.

Mode -2- (flash code output) is not envisaged with electronic heating system. Modes -3- (self-test) and -4- (workshop code) apply only to fault reader V.A.G 1551 and vehicle system tester V.A.G 1552 and are described in the appropriate operating instructions.

Available functions

1)    With VAS 5051, control unit version is always displayed during self-diagnosis.

2)    Final control diagnosis can only be performed up to an engine speed of 3000 rpm and only at vehicle speeds of less than 5 km/h.

3)    On this vehicle, basic settings (e.g. country version, LHD/RHD) of operating and display unit for air conditioner/Climatronic -E87 (heating) are encoded by dash panel insert. Data are transferred via convenience data bus to -E87 (heating); currently valid code is displayed in measured value block . Direct entry of code into -E87 (heating) is possible for certain equipment versions (e.g. heated windscreen or sun roof with solar cells).

=> Electrical System; Repair Group 01

4)    Chassis number transmitted via convenience data bus is stored on initial commissioning of -E87 (heating). If -E87 (heating) of this type is transferred to a different vehicle, this chassis number must be erased by way of "Adaption" function.

Notes:

• ◆ This Workshop Manual describes self-diagnosis using the vehicle diagnostic, testing and information system VAS 5051.
• ◆ Self-diagnosis can be performed in the same manner with fault reader V.A.G 1551 or vehicle system tester V.A.G 1552. In order to be able to furnish proof of faults in the event of subsequent enquiries, it is appropriate to connect up the vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 before erasing fault memory and to print out the faults present (V.A.G 1552 does not feature a printer).

• ◆ If a new operating and display unit for air conditioner/Climatronic -E87(heating) has been fitted and basic setting not performed following installation, fault "Basic setting not performed" is displayed in fault memory.
• ◆ Heating system control is not terminated on starting self-diagnosis; it is however deactivated on selecting the following functions:

- Final control diagnosis

- Performing basic setting

Control remains fully operational on selecting all other functions.

• ◆ Component fitting locations can be found onPage 80-1 onwards.