Volkswagen Workshop Service and Repair Manuals

Notes:

• ◆ It is extremely important to keep to the tightening torque of 20 Nm to ensure the knock sensors perform perfectly.
• ◆ Only gold-plated contacts may be used when servicing the knock sensor connector contacts.

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Test box V.A.G 1598/22
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test conditions

• ● Knock sensor fault recognised by self-diagnosis , interrogating and erasing fault memory.

Test sequence

• ‒ → Pull 2 pin connector off knock sensor -arrow-.

• ‒ → Connect test box V.A.G 1598/22 to control unit wiring harness.

• ‒ → Check wiring between test box and 2 pin connector for open circuit using current flow diagram.
       Contact 1+socket 68
       Contact 2+socket 60
       Wire resistance: Max. 1.5ω
• ‒ 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.
• ‒ Carry out test drive.

Observe the valid safety precautions when carrying out a 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 (G61) , item 6 .