Knock Sensors, Checking

Knock Sensors, Checking







Recommended special tools and equipment
- V.A.G1526A hand multimeter
- V.A.G1594A connector test kit
- V.A.G1598/31 test box

NOTE:
- Knock Sensor (KS) 1 -G61- and Knock Sensor (KS) 2 -G66- themselves cannot be electrically tested.
- When servicing terminals in harness connector of knock sensors, use only gold-plated terminals.
- For the Knock Sensors to function properly, it is important for tightening torque to be exactly 20 Nm.
- Check harness connector from knock sensor to wiring harness for corrosion.

Test requirement:
- Ignition switched off.

Checking knock sensor wiring







- Disconnect harness connector for Knock Sensor (KS) 1 -G61- (item 1) or Knock Sensor (KS) 2 -G66- (item 4).

NOTE:







Coolant reservoir screw (arrow) must be removed and coolant reservoir must be placed to the side in order to access harness connector. The coolant hoses remain connected.







- Check all three terminals at knock sensor connector for short circuit to each other (terminal 1+2, 1+3, 2+3).

Specified value: Infinite Ohms (no continuity) - the wires must not have any connection to each other.

- If there is a connection, replace knock sensor.

If no malfunction can be found:

Check wires from knock sensors to Engine Control Module (ECM).
- Connect test box to wiring harness of Engine Control Module (ECM) ECM is not connected.







- Check the following wire connections for open circuit according to wiring diagram:

- Knock Sensor (KS) 1 -G61- (bank 1)

Harness connector Test box
Terminal Socket
1 (signal) 106
2 (Ground -GND-) 99
3 (shielding) 108

- Knock Sensor (KS) 2 -G66- (bank 2)

Harness connector Test box
Terminal Socket
1 (signal) 107
2 (Ground -GND-) 99
3 (shielding) 108

Specified value: Wire resistance max 1.5 Ohms

- Check wires for short circuit to each other as well as to B+ and Ground (GND).

Specified value: Infinite Ohms (no continuity)

- If necessary, repair wire connection.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check DTC memory.
2. Erase DTC memory.
3. Generate readiness code. With Generic Scan Tool

- End diagnosis and switch ignition off.