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.
• ◆ If fault codes 00524 or 00540 are recognised, check security of ancillaries. The vibrations from loose components are recognised as "knocking noises".

• ◆ Only gold-plated contacts may be used when servicing the knock sensor connector contacts.

Special tools, testers, measuring instruments and auxiliary items required

• ◆ → Hand multimeter V.A.G 1526 or multimeter V.A.G 1715

• ◆ → V.A.G 1598/22 Test box
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test sequence

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

Knock sensor 1 (G61)

• ‒ → Pull the 2 pin connector (arrow) off knock sensor 1.

Knock sensor 2 (G66)

• ‒ → Pull the 2 pin connector (arrow) off knock sensor 2.

• ‒ Measure resistance between knock sensor contacts 1+2.
       Specification: ∞ω

• ‒ → Check wiring between test box and 2 pin connector for open circuit using current flow diagram.
            G61:     G66:
       Contact 1+socket     68     60
       Contact 2+socket     67     67
       Wire resistance: Max. 1.5 ω
• ‒ Additionally check wires for short to one another.
            G61:     G66:
       Contact 1+socket     67     67
       Specification: ∞ω

If no wiring fault is detected:

• ‒ Remove insulation tray.

=> General body repairs; Repair group 50; Removing insulation tray

• ‒ Loosen appropriate 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 (fault again in fault memory):

• ‒ Replace appropriate knock sensor (G61 and/or G66) =>Page 28-8 .