Knock Sensors, Testing

Knock Sensors, Testing







Special tools and equipment
- VAG 1526 A
- VAG1594 A
- VAG 1598/31

NOTE:
- It is not possible to carry out an electrical test of the knock sensors themselves (-G61- and -G66-).
- Always use gold-plated contacts when repairing the knock sensor connectors.
- To ensure that the knock sensors function properly it is important to keep exactly to the specified tightening torque of 20 Nm.
- Check for corrosion in connection between knock sensor and wiring harness.

Knock sensors with 3-pin connector

Testing knock sensor wiring






- Unplug the connector for knock sensor (KS) 1 -G61- -Item 1- or knock sensor (KS) 2 -G66- -Item 2- in the engine compartment.







- Test for short circuits between all three contacts in the knock sensor connector (contacts 1+2, 1+3 and 2+3).

- Specification: Infinity Ohms (no continuity) - there must be no connection between any of the contacts.

- If there is a connection between the contacts, fit a new knock sensor.
- If there is no short circuit, test wiring for knock sensors.

Testing wiring between knock sensors and engine control module
- Connect test box VAG 1598/31 to wiring harness for engine control module. Do not connect to the engine control module itself. Scan Tool Testing and Procedures
- Test for open circuit and short to positive or Ground in the following wiring connections:







- Knock sensor 1 -G61 (cylinders 1/2)

Connector Contact Test box VAG 1598/31 Socket
1 (signal) 106
2 (Ground) 99
3 (screening) 106







- Knock sensor 2 -G66 (cylinders 3/4)

Connector Contact Test box VAG 1598/31 Socket
1 (signal) 107
2 (Ground) 99
3 (screening) 108

- Correct any open/short circuit as necessary.

Knock sensors with 2-pin connector
- Remove knock sensor.







- Unplug connector.
- Connect multimeter (resistance test range) between contacts 1 and 2 of knock sensor.
- Specification: Infinity Ohms (no continuity)

If the specification is not attained:
- Install a new knock sensor.

Tightening torque: 20 Nm

If the specification is obtained:
- Connect test box VAG 1598/31 to wiring harness for engine control module. Do not connect to the engine control module itself. Scan Tool Testing and Procedures
- Test for open circuit and short to positive or Ground in the following wiring connections:







- Knock sensor (KS) 1 -G61- (cylinders 1/2)

Connector Contact Test box VAG 1598/31 Socket
1 (signal) 106
2 (Ground) 99

- Knock sensor (KS) 2 -G66- (cylinders 3/4)

Connector Contact Test box VAG 1598/31 Socket
1 (signal) 107
2 (Ground) 99

- Correct any open/short circuit as necessary.