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Interrogating and erasing fault memory > < Connecting up vehicle diagnostic, testing and information system VAS 5051 and selecting engine electronics control units

A3 Mk1

Motronic injection and ignition system (4-cyl.)
Self-diagnosis of Motronic
Connecting up fault reader V.A.G 1551 and selecting engine electronics control unit
 
A01-0001

Test requirements

  • ● Fuses for engine electronics OK
  • ● Fuel pump relay OK
  • ● Battery voltage at least 11 V
  • ● Earth connections at engine and gearbox OK
  • ‒ Switch off ignition.
  • ‒ → Connect vehicle diagnostic, testing and information system VAS 5051 with diagnostic lead VAS 5051/1. Alternatively, use can be made of diagnostic wire V.A.G 1551/3 to connect up fault reader V.A.G 1551.

Note:

  • ◆ Diagnostic connection is located in front left knee restraint.
Attention:
  • ◆ On test drives the vehicle diagnostic, testing and information system VAS 5051 or the fault reader V.A.G 1551 must only be secured on the rear seat and operated from there.
  • ◆ Observe the safety precautions

Note:

The following description refers solely to implementation of self-diagnosis using fault reader V.A.G 1551.

Proceed in line with equipment operating instructions if use is made of vehicle diagnostic, testing and information system VAS 5051.
 
→ Indicated on display:
V.A.G SELF-DIAGNOSIS    HELP
1 - Rapid data transfer 1)
2 - Flash code output1)

    1)    Displayed alternately

  • ‒ If display remains blank, check diagnostic wiring:

=> "Current Flow Diagrams, Electrical Fault-finding and Fitting Locations" binder; "Diagnostic Wire" fault-finding program

Depending on desired function => "Available functions" table, Page 01-2:

  • ‒ Switch on ignition.
  • or
  • ‒ Start engine.
  • ‒ Switch on printer of fault reader by pressing Print key. Lamp in key must light.
  • ‒ Press key 1 for "Rapid data transfer".
 
→ Indicated on display:
Rapid data transfer    HELP
Enter address word XX

 
→ Press keys 0 and 1 for address word "Engine electronics" and confirm entry with Q key.
Rapid data transfer    Q
01 - Engine electronics

Note:
 
→ If one of the adjacent messages appears on the display, perform fault-finding in line with fault-finding program for diagnostic wire.
Rapid data transfer    HELP
No control unit response
 
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
Rapid data transfer    HELP
Fault in communication link
 
Rapid data transfer    HELP
K-wire not switched to earth
 
Rapid data transfer    HELP
K-wire not switched to positive
 
→ Fault reader V.A.G 1551 displays control unit identification, e.g.:
8D1906018.. 1.8l    R4S/5V MOTR HS    D..⇒
Code 10500    WSC 06388

- 8D1906018..

Control unit number
(refer to Parts List)

- 1.8l

Engine capacity

- R4S/5V

In-line engine, 4-cyl. normally aspirated / 5-valve

- MOTR

Motronic

- HS
- AT

HS = Manual gearbox
AT = Automatic gearbox

- GRA

Only displayed for vehicles with cruise control system

- ...

Data level (software version) of control unit

- Code 10500

Control unit code (encoding
=> Page 01-81)

- WSC 06388

Workshop code from V.A.G 1551 with which encoding was last performed

Notes:

  • ◆ Incorrect encoding can lead to poorer emission values and greater strain on the automatic gearbox due to gearshift jolts.
  • ◆ Incorrect encoding also results in non-existent faults being stored in the fault memory.

If encoding does not coincide with corresponding version in vehicle:

  • ‒ Check engine control unit encoding
    => Page 01-81, Encoding engine control unit
  • ‒ Press ⇒key.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX

Note:

Pressing HELP key prints out a list of possible functions.

Interrogating and erasing fault memory > < Connecting up vehicle diagnostic, testing and information system VAS 5051 and selecting engine electronics control units