Knock sensors, checking: Notes
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 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
- Ground (GND) connections between engine and chassis must be OK.
- mounting bolts of knock sensors tightened to 20 Nm.
- Ignition switched off.
Test sequence
Cylinder bank 1
- Disconnect the 3-pin harness connector to Knock Sensor (KS) 1 -G61- (arrow).
Cylinder bank 2
- Disconnect the 3-pin harness connector to Knock Sensor (KS) 2 -G66- (arrow).
Cylinder bank 1 and 2
NOTE:
- Cylinder bank 1 = in direction of travel, right.
- Cylinder bank 2 = in direction of travel, left.
- Before disconnecting harness connectors, mark allocation to component.
Checking resistances
- Measure resistance between terminals 1 + 2, 1 + 3 and 2 + 3 at the connections to the respective knock sensors.
Specified value: ∞ Ω
If specified value is not obtained:
- Replace the respective knock sensor:
Cylinder bank 1
- Knock Sensor (KS) 1 -G61-. Refer to Ignition components, removing and installing , Ignition components, removing and installing ,
Cylinder bank 2
- Knock Sensor (KS) 2 -G66-. Refer to Ignition components, removing and installing , Ignition components, removing and installing .
- Erase DTC memory of Engine Control Module (ECM). Refer to Diagnostic mode 4: Reset/erase diagnostic data , Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Refer to Readiness code, generating .
If specified value is obtained:
- Check wires according to wiring diagram. Refer to Checking wiring .