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

Test conditions

• ● Fault on one or both knock sensors recognised by self-diagnosis
• ● Fault memory erased

Test sequence

• ‒ → Detach brown 3 pin connector to knock sensor 1 (G61) -1- or black 3 pin connector to knock sensor 2 (G66) -2-.
• ‒ Measure resistance between the contacts 1+2, 1+3 and 2+3 at connection to knock sensor.
       Specification ∞ω

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.
• ‒ Check wiring between test box and 3 pin connector for open circuit according to current flow diagram.
            G61:     G66:
       Contact 1+socket     34     57
       Contact 2+socket     32     56
       Contact 3+socket     10     55
       Wire resistance: Max. 1.5 ω
• ‒ Additionally check wires for short to one another.
       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.