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

Note:

Vehicle system tester V.A.G 1552 can be used instead of fault reader V.A.G 1551, but in this case no print-out can be produced.

Test conditions

Fuses for engine electronics OK
Battery voltage at least 11 V
Fuel pump relay OK

Connect fault reader with diagnostic cable V.A.G 1551/1 to the diagnostic sockets as follows:
Black connector to "black" diagnostic socket

V.A.G self-diagnosis
HELP
1 - Rapid data transfer*
2 - Flash code output*
Readout on display:

* Appears alternately

If no readout appears in the display, check voltage supply to black connector.

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations binder, Fault-finding program "Diagnostic wiring"

White connector to "white" diagnostic socket
Blue connector is not required.

Note:

Additional operating instructions can be displayed by pressing the HELP key of V.A.G 1551.
Use the ⇒ button to move on to the next step of the program.

Switch ignition on.
Switch on printer with PRINT key (indicator lamp in key illuminates).

Press key 1 for "Rapid data transfer" mode.

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

Press keys 0 and 1

(01 enters address word "Engine electronics").

Rapid data transfer
Q
01
Engine electronics
Readout on display:

Confirm entry with Q key.

Rapid data transfer
Tester sends address word
01
Readout on display:

Note:

When the address word 00 has been entered and confirmed with the Q button, an automatic test sequence is implemented (fault memory interrogation of all systems with rapid data transfer).

Rapid data transfer
HELP
Control unit does not answer
Readout on display:

Rapid data transfer
HELP
Communications
problem
If one of these messages appears in the display, carry out fault finding of diagnostic wires.

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations binder, Fault-finding program, "Diagnostic wiring"

Rapid data transfer
HELP
K-wire not switching to earth

Rapid data transfer
HELP
K-wire not switching to positive

After rectifying the cause of the fault, enter address word 01 for brake electronics again and confirm with the Q key.

4D0907557H
4,2L V8/4V
MOTR HS
D. ⇒
Coding 04212
WSC
06388
The control unit identification and the coding appear in the display.

The readout contains the following information:

4D0907557H · Control unit number (current control unit version - see Parts Programme)
4.2 L · Engine capacity
V8/4V · Type of engine / (V engine, 8-Cyl., 4-valve)
MOTR · Motronic
HS · Handshift (manual gearbox)
D... · Software version of control unit
Coding 04212 · Coding of engine control unit
WSC 06388 · Workshop Code from V.A.G 1551 used to perform the last coding

Note:

Incorrect coding can result in increased exhaust emission levels and in non-existent faults being stored in the fault memory.