Operation CHARM: Car repair manuals for everyone.

Knock Sensor, Checking



Knock Sensors, Checking

- Contact surfaces between knock sensor and cylinder block must be free of corrosion, dirt and grease.
- To ensure problem-free function of knock sensors, it is important that torque specification of 20 Nm be adhered to exactly.
- Use only gold-plated terminals when servicing terminals in harness connector of knock sensors.

Recommended Special Tools, Workshop Equipment, Testers, Measuring Instruments and Auxiliary Items
- V.A.G 1526 portable multimeter or V.A.G 1715 multimeter.
- Adapter set V.A.G 1594
- Wiring diagram

Test Conditions
- Knock sensor securing bolt tightened to 20 Nm.
- Ignition switched off.

Checking Resistances and Wiring - Engine Codes AMU, ATC
- Disconnect each sensors connector in engine compartment.
- Measure resistance between terminals 1 + 2, 1 + 3 and 2 + 3 at connectors to knock sensors.







- Specification: Infinity Ohms

If the specification is not obtained:
- Replace knock sensor(s)

If the specification is obtained:
- Connect test box to ECM wiring harness. Test Box, Connecting For Wiring Test
- Check wiring between test box and connector for open circuit according to wiring diagram.







- Knock Sensor (KS) 1 -G61 - (cylinder 1/2)

Connector Knock Sensor V.A.G 1598/31 Test box socket
(KS) 1 -G61- terminal
1 (signal) 106
2 (Ground -GND-) 99
3 (Shielding) 108

- Knock Sensor (KS) 2 -G66- (cylinder 3/4)

Connector Knock Sensor V.A.G 1598/31 Test box socket
(KS) 2 -G66- terminal
1 (signal) 107
2 (Ground -GND-) 99
3 (Shielding) 108

- Check wires for short circuit to each other.

Checking Resistances and Wiring - Engine Codes AWP, BEA

- Remove Knock Sensor (KS).







- Disconnect connector.
- Connect multimeter between terminal 1 and 2 of Knock Sensor (KS) for resistance measurement.

- Specification: Infinity Ohms (no continuity)

If the specification is not obtained:
- Replace knock sensor(s)

If the specification is obtained:
- Connect test box to control module wiring harness. Test Box, Connecting For Wiring Test
- Check wiring between test box and connector for open circuit according to wiring diagram.







- Knock Sensor (KS) 1 -G61- (cylinder 1/2)

Connector terminal V.A.G 1598/31 Test box socket
1 (signal) 106
2 (Ground -GND-) 99

- Knock Sensor (KS) 2 -G66- (cylinder 3/4)

Connector terminal V.A.G 1598/31 Test box socket
1 (signal) 106
2 (Ground -GND-) 99

- Check wires for short circuit to each other.

- If no fault is detected in the wiring, replace the respective knock sensor:
- Erase DTC memory of ECM. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Generate Readiness Code