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

Test conditions

• ● Fault "00524 Knock sensor 1-G61" recognized 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 circuit.
       Sockets: 19+39, 39+45, 19+45
       Specification: ∞ω

If no short is detected:

• ‒ → 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.
• ‒ Carry out test drive.

• During the road test the following operating conditions must be fulfilled:
• ‒ The coolant temperature must exceed 80 °C .
• ‒ When the temperature is reached, the operating conditions
       Idling
       Part throttle
       Full throttle
       Overrun
  must be attained several times.
• ‒ At full throttle the speed must exceed 3500 rpm.

• ‒ Again interrogate the control unit fault memory.

If the fault is still present:

• ‒ Replace knock sensor
  =>Page 28-4 , item 16 .