Knock Sensor: Service and Repair

12 14 600 Removing/replacing Knock Sensors (N52, N52K, N51)







IMPORTANT:
Aluminium magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
Aluminium screws/bolts are permitted with and without colour coding (blue).

For reliable identification:
Aluminium screws/bolts are not magnetic.
Jointing torque and angle of rotation must be observed without fail (risk of damage).







Necessary preliminary tasks:
- Read out fault memory of DME control unit
- Turn off ignition
- Disconnect battery negative lead
- Remove intake plenum







Unlock plug (1) and remove.







Release screws on both knock sensors (1) and remove knock sensors (1).

Installation:
Replace aluminium screws.
Tightening torque 12 14 1AZ.







Installation:
Clean support face of knock sensors on engine block.







NOTE:
Check stored fault messages.
Delete fault memory.