Volkswagen Workshop Service and Repair Manuals

Special tools, testers and auxiliary items

• ◆ Test box V.A.G 1598/18
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Diode test lamp V.A.G 1527
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Checking voltage supply

• ‒ Pull 3 pin plug off ignition transformer.

• ‒ Connect multimeter using aux. cables from V.A.G 1594 to measure voltage at contacts 1+3 of connector.
• ‒ Switch off ignition.
• ‒ Measure voltage between contacts 1+3.
       Specification: 9...14.5 V
• ‒ Switch off ignition.

If the specification is not obtained:

• ‒ Check the wiring between 3 pin connector and relay plate for open circuit using current flow diagram.
       Contact 1+relay plate
       Contact 3+relay plate
       Wire resistance: max. 1.5 ω

If no wiring fault is detected and voltage was present between contacts 1+3:

• ‒ Replace ignition transformer (N152) , item 7 .

If no wiring fault is detected and no voltage was present between contacts 1+3:

• ‒ Renew Motronic control unit (J220)
  , item 12 .

• ‒ Read-out the readiness code=> Page 01-35 .

Checking activation

• ‒ Separate the engine central connector => Page 24-2 , item 11 .
• ‒ → Connect diode test lamp V.A.G 1527 with aux. cables from V.A.G 1594 and adapters V.A.G 1594/15 to contacts 2+3 of the connector.
• ‒ Operate starter and check ignition signal from Motronic control unit.
       LED must flicker
• ‒ Switch off ignition.

The LED does not flicker:

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom -arrow-.
• ‒ Check the wiring between 3 pin connector and test box for open circuit according to current flow diagram.
       Contact 2+socket 8
       Wire resistance: max. 1.5 ω
• ‒ Additionally check the wiring for short to one another.
       Contact 1+socket 8
       Contact 3+socket 8
       Specification: ∞ω

If no wiring fault is detected and voltage was present between contacts 1+3:

• ‒ Renew Motronic control unit (J220)
  => Page 24-8 , item 12 .
• ‒ Read-out the readiness code=> Page 01-35 .

If the voltage supply and activation is OK.:

• ‒ Reconnect 3 pin plug and H.T. cable to ignition transformer.

• ‒ → Connect diode test lamp with aux. cables and clamps to the contacts 1 and 15 on ignition transformer.

• ‒ Operate starter.
       The LED must flicker,
  if necessary renew output stage.