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

Checking resistances and wires (Vehicles with engine code AFP)

Knock Sensor (KS) 1 -G61-







- Disconnect white 3-pin harness connector for knock sensor 1 (arrow).

Knock Sensor (KS) 2 -G66-







- Disconnect brown 3-pin harness connector for knock sensor 2 (arrow).







- Measure resistance between terminals 1 + 2, 1 + 3, and 2 + 3 at connectors to knock sensors.
Specified value: Infinity 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 3-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: Infinity Ohms

If no malfunctions are found in wires:
- Replace the respective knock sensor:
- Knock Sensor (KS) 1 -G61-, item 15 ,
- Knock Sensor (KS) 2 -G66-, item 11 .

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
Clearing Diagnostic Trouble Codes

- Generate readiness code.
Monitors, Trips, Drive Cycles and Readiness Codes

Checking resistances and wires (Vehicles with engine code BDF)

Knock Sensor (KS) 1 -G61-







- Disconnect 3-pin harness connector at right cylinder head for knock sensor 1 (arrow).







- Measure resistance between terminals 1 + 2, 1 + 3, and 2 + 3 at harness connector for Knock Sensor (KS) 1 -G61-.
Specified value: Infinity Ohms

Knock Sensor (KS) 2 -G66-







- Disconnect 2-pin harness connector from knock sensor 2 (arrow, at intake manifold side of cylinder block)







- Now measure resistance between terminals 1 + 2 at connector for knock Sensor (KS) 2 -G66-.
Specified value: Infinity Ohms

- Connect test box to control module wiring harness, connect test box for wiring test.
Test Box, Connecting For Wiring Test

Knock Sensor (KS) 1 -G61-







- Check wires between test box and 3-pin connector for open circuits according to wiring diagram.
Terminal 2 + socket 106
Terminal 2 + socket 99
Terminal 3 + socket 108

Wire resistance: max: 1.5 Ohms

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

Knock Sensor (KS) 2 -G66-







- Now check wires between test box and 2-pin connector for open circuits according to wiring diagram.
Terminal 2 + socket 107
Terminal 2 + socket 99

Wire resistance: max: 1.5 Ohms

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

If no malfunctions are found in wires:
- Replace the respective knock sensor:
- Knock Sensor (KS) 1 -G61-, item 7
- Knock Sensor (KS) 2 -G66-, item 17

- 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