Knock Sensor: Testing and Inspection

NOTE:
- To functionally check knock sensors, refer to Read measuring value block, display group 015 and/or 016.
- Component locations, refer to "Component Overview - I " Locations
- Knock sensors can not be checked electrically, check DTC memory.
- Use connector insertion tool 3247 for knock sensor removing and installing.
- It is important that exact knock sensor tightening torque of 20 Nm (15 ft lb) be maintained to make sure that there is proper knock sensor function.
- Visually check the knock sensor connector for corrosion.
- When repairing or replacing knock sensor connector terminals, ONLY replace with gold plated terminals.


Checking knock sensor wiring
- Disconnect knock sensor harness connectors in engine compartment.







- Check all three terminals in knock sensor harness connector for shorting to each other.
- Wires must not be short circuited to each other

If there is a short circuit:
- Replace knock sensor.







Checking wiring between knock sensor and ECM
- Connect VAG 1598/19 test box to ECM harness connector.
- Check wiring for continuity or short between knock sensor and ECM using wiring diagram.

Terminal assignments (inside connector)
1 - Ground (GND) wire
2 - Signal wire
3 - Shield

Knock Sensor (KS) 1 -G61-
- Check signal wire for continuity between harness connector terminal 2 (in engine compartment) and test box socket A13.
Specified value: max. 1 ohm
- Check Ground (GND) wire for continuity between harness connector terminal 1 and test box socket A14.
Specified value: max. 1 ohm
- Check shielding for continuity between harness connector terminal 3 (in engine compartment) and engine Ground.
Specified value: max. 1 ohm

If specified values are not obtained, repair open or short circuit.

Knock Sensor (KS) 2 -G66-
- Check signal wire for continuity between harness connector terminal 2 (in engine compartment) and test box socket A15.
Specified value: max. 1 ohm
- Check Ground (GND) wire for continuity between harness connector terminal 1 and test box socket A14.
Specified value: max. 1 ohm
- Check shielding for continuity between harness connector terminal 3 (in engine compartment) and engine Ground.
Specified value: max. 1 ohm

If the specified values are not obtained:
- Eliminate open or short circuit in wiring.







- knock sensor 1 (bank 1):

Knock sensor terminal number ECM connector A or engine ground (GND)
1 (Signal) A13
2 (Ground) A14
3 (shield) Engine Ground (GND)

- Knock sensor 2 (Bank 2):

Knock sensor terminal number ECM connector A or engine ground (GND)
1 (Signal) A15
2 (Ground) A14
3 (Shield) Engine Ground (GND)