Knock Sensor: Testing and Inspection

Knock Sensors, Checking

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
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Requirements
- Knock sensor mounting bolt tightened to 20 Nm.
- Ignition switched off.

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







- 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







- Check wires for short circuit to each other.

Specified value: Infinite Ohms

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

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