Connecting fault reader V.A.G 1551 and selecting engine electronic control unit — AUDI

ADW
Test requirements:

Supply voltage of vehicle electrical system OK
Engine fuses OK

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

Fuel pump relay -J17 and current supply relay -J176 OK. Testing => page
28-33
.
earth connections checked.

Test following earth connections for corrosion and poor connection before interrogating fault memory, final control diagnosis, engine basic settings, test of wiring and also before replacing components:

Earth attachment point at left of cylinder head -arrow-.
Battery earth strap and earth strap between engine and side member.

Repair any damaged earth connections.

Take off the cover of the auxiliary relay carrier 1 in the left of the plenum chamber.
Connect fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 to diagnostic connectors on relay panel as follows using wire V.A.G1551/1:
With the ignition switched off, connect black connector to black diagnostic connection.

V.A.G - SELF DIAGNOSIS
HELP
1 - Rapid data transfer 1)
2 - Flash code output 1).
Indicated on display:

1)
appears alternately

Note:

If the display remains blank, test voltage supply to black diagnostic connector => page
01-77
.

Connect white connector to white diagnostic connection (blue connector is not used).

Depending on the which function is required => "Available functions" table, page
01-7
:

Switch the ignition on.

or

Start the engine.
Switch on the fault reader printer with the print key. The indicator lamp in the key must light up.
Enter "1" for "Rapid data transfer".

Rapid data transfer
HELP
Enter address word XX
Indicated on display:

Note:

Address word 00 implements automatic test sequence, i.e. interrogation of fault memory via rapid data transfer for all vehicle systems with a self-diagnosis capability.

Enter "01" for address word "Engine electronics" and confirm entry with Q key.

039906024A
Digifant
1.75
1566
⇒
Code 00002
WSC 12345
The display on the fault reader V.A.G 1551 will show the control unit identification code (example).

Note:

The control unit identification can be printed out by pressing the PRINT key on fault reader V.A.G 1551.

Control unit identification (example)

- 39.906.024 A · Part no.; assignment / => Parts catalogue
- Digifant 1.75 · Digifant fuel injection and ignition system.
- 1566 · Data status (software status) of control unit
- Coding 00002 · Control unit code
- WSC 12345 · Workshop Code of V.A.G 1551 with which encoding was last performed

Note:

If no data link can be established with the control unit =>page
01-78
.

Press the ⇒key.

Rapid data transfer
HELP
Select function XX
Indicated on display (function selection):

Note:

After entering the function "01"for "Interrogating control unit version" and confirming with the Q key, you may display the control unit identification again.

Available functions

Fault reader V.A.G 1551 fault reader or vehicle system tester V.A.G 1552 · Ignition on, / engine stopped · Engine idling · Vehicle running · page
Address words
01 · Engine electronics · yes · yes · yes · 01-2
00 · Automatic test routine · yes · yes · yes · 01-4
Functions
01 · Interrogating control unit version · yes · yes · yes · 01-2
02 · Interrogating fault memory · yes · yes · yes · 01-8
03 · Final control diagnosis · yes · no · no · 01-36
04 · Basic setting · no · yes · no · 01-39
05 · Erase fault memory · yes · yes · yes · 01-8
06 · End of output · yes · yes · yes · 01-8
07 · Coding control unit · yes1. · no · no · 01-43
08 · Reading measured value block · yes · yes · yes · 01-45

1)
As of control unit no. 39.906.024 A