Volkswagen Workshop Service and Repair Manuals

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ → V.A.G 1551 Fault reader

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.

All functions of V.A.G 1551/1552 can also be carried out with the new tester V.A.S 5051. Connecting VAS 5051 .

• ◆ → V.A.G 1551/3A Cable

Test conditions

• ● → The fuses No. 1, 3, 15, 24, 30, 31, 34, 36 and 40 must be OK.
• ● Earth connection between engine (on gearbox bell housing) and body (below battery) OK.
• ● Earth connection in plenum chamber OK.
• ● The battery voltage must be at least 11.5 V.
• ● If the vehicle is equipped with an air conditioning system, this must be switched off.
• ● All electrical consumers, e.g. lights and rear window heating must be switched off.

Work sequence

• ‒ → Pull cover -1- off in direction of arrow.
• ‒ Connect fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3A.

After the fault reader has been connected:

• ‒ Depending upon desired function:
  Switch ignition on
       or
  Start engine , Table "Selectable functions".

Notes:

• ◆ If the display remains blank, check voltage supply for diagnostic connection according to fault finding programme:

=> Current flow diagrams, Electrical fault finding and Fitting locations

• ◆ 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:

* Appears alternately

• ‒ Operate fault reader taking into account the information on the display:
• ‒ Press key 1 for "Rapid data transfer".
• ‒ Press keys 0 and 1 for address word "Engine electronics" and confirm entry with Q key.

• ◆ 030906032G = Part No. of control unit (for up-to-date control unit version see parts film)
• ◆ ME 7.5.10 = System designation and version
• ◆ 2921 = Program level number
• ◆ Coding XXXXX = Control unit coding
• ◆ WSC xxxxx = Workshop code from V.A.G 1551, of the workshop who carried out the last coding. (If the factory coding has not been changed, WSC 00000 appears)

Note:

Replace control unit if the control version displayed does not correspond to the vehicle

=> Page 24-135 .

An incorrectly coded engine control unit leads to:

• ◆ Engine running faults (gear change jerks, load change jerks, etc.)
• ◆ Increased fuel consumption
• ◆ Increased exhaust gas emissions
• ◆ Faults stored in fault memory which are not actually present
• ◆ Functions will not be performed (Lambda regulation, activation of the activated charcoal filter system, etc.).

• ‒ Press ⇒key.

• ‒ Further measures see repair procedures.