Audi Workshop Service and Repair Manuals > A4 Mk2 > Power unit | Direct petrol injection and ignition system (8-cyl. 4.2 ltr. 4-valve), RS 4 | Ignition system, glow plug system | Servicing ignition system

Removing and installing knock sensors

Fitting locations in engine compartment

1 -	Intake manifold flap potentiometer -G336-

2 -	Intake manifold flap valve -N316-

3 -	Electrical connector “brown” for knock sensor 4 -G199-

4 -	Electrical connector “black ” for knock sensor 3 -G198-

5 -	Electrical connector “brown” for knock sensor 2 -G66-

6 -	Electrical connector “black ” for knock sensor 1 -G61-

Removing

WARNING

t	The fuel system operates under high pressure. The pressure in the high-pressure part of the injection system must be reduced to a residual pressure prior to opening the system → Chapter.

t	A clean cloth must then be wrapped around the connection and the residual pressure dissipated by carefully loosening the connection.

t	Observe notes on procedure for disconnecting the battery → Rep. Gr.27.

–	Remove intake manifold → Chapter.

Remove appropriate knock sensor on cylinder bank (right-side).

2 -	Knock sensor 1 -G61-

9 -	Knock sensor 2 -G66-

Remove appropriate knock sensor on cylinder bank (left-side).

8 -	Knock sensor 3 -G198-

1 -	Knock sensor 4 -G199-

Installing

–	Re-install whichever knock sensor was removed.

Note

The tightening torque influences the function of the knock sensor.

Tightening torques for knock sensors: refer to exploded view of ignition system → Chapter.

–	Install intake manifold → Chapter.

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