Necessary preliminary work

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Read out the fault memory of the DME control unit.
Switch off ignition.
Disconnect BATTERY EARTH LEAD .
Remove LEFT INTAKE PLENUM .

Unlock and disconnect connector (1) on both knock sensors.

Release screws on both knock sensors (2).

Tightening torque 13 62 5AZ .

Remove knock sensors (3).

Fig 1: Identifying Knock Sensors, Connector And Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Clean contact surface of knock sensors on engine block.

Fig 2: Locating Contact Surface Of Knock Sensors On Engine Block

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Check stored fault message.
Delete fault memory.