volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Diesel injection and glow plug system > < Checking ignition transformer output stage
Mono Motronic injection and ignition system
Mono-Motronic injection and ignition system
Checking knock sensor

Engine code AEA only

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
  • ◆ Adapter set V.A.G 1594
  • ◆ Current flow diagram

Test conditions

 
N24-0160
  • ● Knock sensor fault recognised by self-diagnosis

Test sequence

  • ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.
  • ‒ Check wiring and knock sensor for short.
         Sockets: 19+39, 39+45, 19+45
         Specification: ∞ω

If no short is detected:

 
N28-0015
  • ‒ → Pull connector -1- off knock sensor 1 (G61) -2-.
  • ‒ Check wiring between test box and knock sensor for open circuit according to current flow diagram.
         Contact 1+socket 39
         Contact 2+socket 19
         Wire resistance: Max. 1.5 ω
  • ‒ Measure resistance between knock sensor contacts.
         Specification ∞ω

If no wiring fault is detected:

  • ‒ Loosen knock sensor and tighten again to 20 Nm.

If the fault is still present (fault again in fault memory):

  • ‒ Replace knock sensor.

Diesel injection and glow plug system > < Checking ignition transformer output stage