Manufacturer's Scan Tool

Knock Sensors, Checking





Special tools, testers and auxiliary items required

• Multimeter (V.A.G 1526 A)

• Connector test kit (V.A.G 1594 A)

• Test box (VAG1598/31)

Component location => [ (Item 16) ] Locations, => [ (Item 14) ] Locations

• The Knock sensors (G61) and (G66) cannot be tested electrically by themselves..

• Use only gold-plated terminals when repairing the cable connectors for the knock sensors.

• To ensure that the knock sensors function properly it is important to keep exactly to the specified tightening torque of 20 Nm.

• Check connector between knock sensor and wiring harness for corrosion.

Checking knock sensor wiring

- Disconnect Knock sensor 1 (G61) connector - 1 - or Knock sensor 2 (G66) connector- 4 -.





• To gain access to the connector, remove coolant expansion tank bolt (arrow) and move expansion tank to the side. Fuel hoses remain connected.





- Test for short between all three terminals in knock sensor connector (terminals 1+2, 1+3, 2+3).





• Specified value: infinite ohms (no continuity) wiring must not be connected to each other.

- If there is a connection between terminals, install a new knock sensor.

If no malfunction is found:

Checking wiring from knock sensors to ECM

- Connect test box (VAG1598/31) to wiring harness for ECM; do not connect ECM => [ Electrical Testing, with Test Box VAG 1598/31 ] Electrical Testing, With Test Box VAG 1598/31.

- Check for open circuit, short to ground, or short to positive in following wiring connections:

• Knock sensor 1 (G61) (cylinders 1 and 2)









• Knock sensor 2 (G66) (cylinders 3 and 4)









- Repair any open/short circuit as necessary.