With Generic Scan Tool

Check Knock Sensors

Note:
- Contact surfaces between knock sensor and cylinder block must be free of corrosion, dirt and grease.
- For the Knock Sensors to function properly, it is important for tightening torque to be exactly 20 Nm.
- Use only gold-plated terminals when servicing terminals in harness connector of knock sensors.

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirements
- Securing bolt for knock sensors tightened to 20 Nm.
- Ignition switched off.

Checking resistances and wires (Vehicles with engine code AEG)
-Checking resistances and wires (Vehicles with engine code AVH, AZG, BDC).







- Disconnect 2-pin connectors from knock sensors.
1 - Knock Sensor (KS) 1 -G61-
2 - Knock Sensor (KS) 2 -G66-

Note: Before disconnecting harness connectors, mark allocation to component.







- Measure resistance between terminals 1 + 2 at connectors to knock sensors. Specified value: Infinite Ohms
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test







- Check wires between test box and 2-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram. Wire resistance: max. 1.5 ohms







- Also check wires for short circuit to each other.
Specified value: Infinite Ohms

If resistances and wires are OK:
- Replace the respective knock sensor:
- Knock Sensor (KS) 1 -G61-, item 7.
- Knock Sensor (KS) 2 -G66-, item 5.

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code.

Checking resistances and wires (Vehicles with engine code AVH, AZG, BDC)







- Disconnect 2-pin connectors from knock sensors.
1 - Knock Sensor (KS) 1 -G61-
2 - Knock Sensor (KS) 2 -G66-

Note: Before disconnecting harness connectors, mark allocation to component.







- Measure resistance between terminals 1 + 2 at connectors to knock sensors. Specified value: Infinite Ohms
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test







- Check wires between test box and 2-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram. Wire resistance: max. 1.5 Ohms







- Also check wires for short circuit to each other.
Specified value: Infinite Ohms

If resistances and wires are OK:
- Replace the respective knock sensor:
- Knock Sensor (KS) 1 -G61-, item 5
- Knock Sensor (KS) 2 -G66-, item 7

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes