Volkswagen Workshop Service and Repair Manuals

Special tools, testers and auxiliary items

• ◆ Fault reader V.A.G 1551 with cable V.A.G 1551/3

Note:

The vehicle system tester V.A.G 1552 can be used instead of the fault reader V.A.G 1551, however a print-out is not possible.

Test conditions

• ● Fuse 21 OK.

• ● Battery voltage at least 11 V
• ● Earth connections on engine and gearbox OK.
  (Earth connection engine: , Item 22 ).

Work sequence

• ‒ → Unclip cover for diagnostic connections.
• ‒ Connect fault reader V.A.G 1551 with cable V.A.G 1551/3.
• ‒ Depending upon desired function:
  Switch on ignition
       or
  Start engine , Table "Control unit functions".

Notes:

• ◆ If the display does not indicate as described in the work sequence:

=> Fault reader operating instructions

• ◆ If due to an input fault "Fault in the data transfer!" is displayed, pull wire off fault reader, reconnect and repeat work step.

• ‒ Operate fault reader taking into account the information on the display:
• ‒ Input 1 for "Rapid data transfer".
• ‒ Input 01 for address word "Engine electronics" and confirm with Q.

• ◆ 037 906 258K = Part No. of the control unit (for latest control unit version see parts catalogue)
• ◆ Engine 20Q = 2.0 ltr. cross flow engine
• ◆ 400101-S = Programme level number and version
• ◆ Coding 2 AG = Coding variants

• ‒ Checking control unit coding:

Note:

Correct control unit number details and coding are only given at idling speed.

If the coding differs from the vehicle version, then:

• ‒ Checking control unit coding => Page 01-7
• ‒ Press ⇒ key.

• ‒ Further measures see repair procedures.