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 1551/3 Cable

Test conditions

• ● Fuse 21 OK.
• ● The battery voltage must be at least 11.5 V.
• ● Earth connection between engine and body must be OK.

Work sequence

• ‒ → Remove ashtray and slide cover for diagnostic connections to left -arrow-.
• ‒ Connect fault reader V.A.G 1551 with cable V.A.G 1551/3.

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:

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

• ◆ 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.

• ◆ 037906018 = Part No. of the control unit (for latest control unit version see parts catalogue)
• ◆ 2.0 ltr. = Engine displacement
• ◆ R4/2V = Engine configuration (4-Cyl. in-line engine, 2-valve)
• ◆ MOTR = System designation (Motronic)
• ◆ HS = Manual gearbox (hand change)
  AT = Automatic gearbox
• ◆ V01 = Programme level number
• ◆ Coding xxxxx = Control unit coding, coding variants of engine control unit => Page 24-123
• ◆ 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)

Notes:

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

=> Page 24-120 .

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.).
• ◆ Reduced gearbox life

If the coding differs from the vehicle version, then:

• ‒ Checking control unit coding => Page 24-122 ,
  coding engine control unit
• ‒ Press ⇒key.

• ‒ Further measures see repair procedures.