Knock Sensors, Checking
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.
Special tools and workshop equipment required
- Multimeter VAG 1526 or Multimeter VAG 1715
- Connector test kit VAG 1594
- Wiring diagram
Test requirements
- Mounting bolts of knock sensors tightened to 20 Nm.
- Ignition switched off.
Test sequence
Knock Sensor (KS) 1 -G61-
-- Disconnect black 3-pin harness connector for knock sensor 1 (arrow).
Knock Sensor (KS) 2 -G66-
-- Disconnect black 2-pin harness connector for knock sensor 2 (arrow).
Checking wires to Engine Control Module (ECM)
-- Connect test box to control module wiring harness, connect test box for wiring test.
Knock Sensor (KS) 1 -G61-
-- 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 Ω
| Component | Connector | Test box |
|---|---|---|
| Knock Sensor (KS) 1 -G61- | Terminal 1 | Socket 106 |
| Terminal 2 | Socket 99 | |
| Terminal 3 | Socket 108 |
-- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: ∞ Ω
If no malfunctions are found in wires:
-- Replace Knock Sensor (KS) 1 -G61-.
-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
-- Generate readiness code.
Knock Sensor (KS) 2 -G66-
-- 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 Ω
| Component | Connector | Test box |
|---|---|---|
| Knock Sensor (KS) 2 -G66- | Terminal 1 | Socket 107 |
| Terminal 2 | Socket 99 |
-- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: ∞ Ω
If no malfunctions are found in wires:
-- Replace Knock Sensor (KS) 2 -G66-.
Final Procedures
After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .