Knock Sensors, Testing

Knock Sensors, Checking

Special tools and equipment






- VAG1526A
- VAG1594A
- VAG1598/31

NOTE:
- Knock Sensor (KS) 1 -G61- and Knock Sensor (KS) 2 -G66- themselves cannot be electrically tested.
- Use only gold-plated terminals when servicing harness connector for knock sensors.
- For the knock sensors to function properly, it is important that tightening torque be exactly 20 Nm.
- Check harness connector from knock sensor to wiring harness for corrosion.






- Disconnect the 3-pin harness connector for knock sensor 1 (G61) -1-
- Measure resistance between terminals 1 + 2, 1 + 3, and 2 + 3 at connectors to knock sensors.
Specification: Infinity ohms






- Disconnect the 3-pin harness connector for knock sensor 2 (G66) -1-
- Measure resistance between terminals 1 + 2, 1 + 3, and 2 + 3 at connectors to knock sensors.
Specification: Infinity ohms

If specified value is not obtained:
- Replace knock sensor(s)

If specified value is obtained:







- Connect VAG1598/31 test box to control module wiring harness. Engine Control Module (ECM) is not connected.
- Check wiring between test box and 3-pin connector for open circuit according to wiring diagram.

G61: G66:
Terminal 2 + socket 106 107
Terminal 2 + socket 99 99
Terminal 3 socket 108 108

Wire resistance: max. 1.5 ohms
- Check wires for shorts among one another.

If no malfunctions are found in wires:
- Loosen the Knock Sensor (KS) and then retighten it with 20 Nm.
- Perform a road test.

The following operating conditions must be obtained during road test:
- Coolant temperature must rise to above 80 degree C.
- Once this temperature is reached, the following conditions:
Idle
Partial throttle
Wide Open Throttle (WOT)
Deceleration mode must be reached several times each.
- Engine speed must be increased to above 3500 RPM during Wide Open Throttle (WOT).

- Check control module's DTC memory again.

If problem persists:
- Replace knock sensor(s)