Volkswagen Workshop Service and Repair Manuals

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
• ◆ Test box V.A.G 1598/18
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Check conditions

• ● The battery voltage must be at least 11.5 V.
• ● On vehicles 08.95 ▸ the fuse No. 15 must be OK.
• ● On vehicles ▸07.95 the Motronic current supply relay J271 must be OK.

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

• ● Alternator OK, checking:

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

Test sequence

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control unit. When doing this the engine must be running at idling speed.
  (Connecting fault reader and selecting engine control unit .)

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

• ‒ Press keys 0, 0 and 2 for "Display group number 2" and confirm entry with Q key.

• ‒ Read off figure displayed in display zone 3.
       Specification: At least 11.5 V
• ‒ Press the ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.

If the specification is not attained:

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.

Checking voltage supply terminal 30

• ‒ Measure supply voltage between test box sockets 1+54 using multimeter and adapter cables from V.A.G 1594:
       Specification: at least 11.5 V

If the specification is not attained:

• ‒ Check wiring connections to relay plate according to current flow diagram.

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

Checking voltage supply terminal 15

• ‒ Measure voltage supply between test box sockets 1+23 using multimeter and cables from V.A.G 1594.
• ‒ Switch on ignition.
       Specification: min. 11.5 V

If the specification is not attained:

• ‒ Check wiring connections to relay plate according to current flow diagram.

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