Knock Sensor, Checking
Knock Sensor 1 -G61-, Knock Sensor 2 - G66- and Knock Sensor 3 -G198-, Checking
NOTE:
- The V8 BiTurbo engine is equipped with a total of three knock sensors.
- Cylinders 1, 2, 3 and 4 are monitored by Knock sensor 1 -G61-. Cylinders 5 and 6 are monitored by Knock sensor 2 -G66-. Cylinders 7 and 8 are monitored by Knock sensor 3 - G198-.
- The actual knock sensors -G61-, -G66- and - G198- cannot be electrically tested (interrogating fault memory).
- Exact compliance with the tightening torque of 20 Nm is essential to proper knock sensor operation.
- Exclusive use is to be made of gold-plated contacts when repairing contacts in knock sensor connectors.
- Check connector between knock sensor and wiring harness for corrosion.
Checking knock sensor wiring
- Disconnect connector of appropriate knock sensor in engine compartment.
- Check all three contacts at knock sensor connector for mutual short circuit (contacts 1+2, 1+3, 2+3).
Specification: No mutual contact between wires (Infinite Ohm)
- Replace knock sensor if there is contact.
- Check knock sensor wiring if no short circuit is found.
Checking wiring between knock sensors and engine control module
- Connect test box V.A.G 1598/31 at wiring harness to engine control module. Actual engine control module is not to be connected. Wiring And Component Check Using Test Box V.A.G 1598/31
- Check wiring between respective sensor connector ...
- ... and engine control module for open circuit and short to positive/Ground.
Knock sensor 1 -G61-
3-pin connector at wiring Test box V.A.G
harness, socket 1598/31,socket
1 (Ground) 99
2 (signal) 106
3 (screen) 108
Knock sensor 2 -G66-
3-pin connector at wiring Test box V.A.G
harness,socket 1598/31,socket
1 (Ground) 99
2 (signal) 107
3 (screen) 108
Knock sensor 3 -G198-
3-pin connector at wiring Test box V.A.G
harness, socket 1598/31, socket
1 (Ground) 99
2 (signal) 31
3 (screen) 108
Resistance: max.1.5 Ohm
- Eliminate open circuit in wiring/short circuit if necessary.
If there is neither an open circuit in the wiring nor a short circuit, replace engine control module.