Volkswagen Workshop Service and Repair Manuals

Special tools, testers, measuring instruments and auxiliary items required

• ◆ 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

Check conditions

• ● Fault is recognised by self diagnosis
• ● Battery voltage at least 11.5 V
• ● Engine speed sender OK, checking
• ● Hall sender OK, checking

Test sequence

• ‒ → Pull ignition cables off ignition transformer and remove ignition cable duct -2-.

Checking voltage supply

• ‒ → Pull 5 pin connector off ignition transformer -arrow-

• ‒ → Check voltage between contacts 1+5 of detached connector.
• ‒ Switch on ignition.
       Specification: Min. 11.5 V
• ‒ Switch off ignition.

If no voltage is present:

• ‒ Check wire between 5 pin connector contact 1 and earth for open circuit according to current flow diagram.
       Wire resistance: Max. 1.5 ω
• ‒ Check wire between 5 pin connector contact 5 and relay plate for open circuit according to current flow diagram.
       Wire resistance: Max. 1.5 ω

Checking activation

• ‒ Remove fuse 18.
• ‒ → Connect diode test lamp V.A.G 1527 using aux. cables from V.A.G 1594 to disconnected connector contacts
       5 and 2 (ignition output 1).
• ‒ Operate starter and check ignition signal from Motronic control unit.
       LED must flicker.
• ‒ Repeat test at contacts
       5 and 3 (ignition output 3),
       5 and 4 (ignition output 2).

• ‒ Switch off ignition

The LED flickers:

• ‒ Replace ignition transformer (N152)
  , item 6 .

The LED does not flicker:

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

• ‒ → Check wiring between test box and 5 pin connector for open circuit according to current flow diagram.
       Contact 2+socket 8
       Contact 3+socket 50
       Contact 4+socket 52
       Wire resistance: Max. 1.5 ω

• ‒ → Check wiring at 5 pin connector for short to one another.
       Contact 2+socket 60
       Contact 2+socket 52
       Contact 3+socket 52
       Specification: ∞ω

If no wiring fault is detected and voltage was present between contacts 1+5:

• ‒ Renew engine electronics control unit .

Checking secondary winding

• ‒ → Check secondary winding at terminal 4 between
       Cyl. 1 and Cyl. 6,
       Cyl. 3 and Cyl. 4,
       Cyl. 2 and Cyl. 5.
  Specification: 3.6... 4.4 kω

If the specifications are not attained:

• ‒ Replace ignition transformer (N152)
  , item 6 .