Testing knock sensor wiring

Disconnect knock sensor 1 -G61- connector -Pos. 1- or knock sensor 2 -G66- connector -Pos. 4-.

Fig 1: Disconnecting Knock Sensor G61 Connector (Pos. 1) Or Knock Sensor G66 Connector (Pos. 4)

Courtesy of AUDI OF AMERICA, INC.

NOTE: To gain access to the connector, remove coolant expansion tank bolt -arrow- and move expansion tank to the side. Fuel hoses remain connected.

Fig 2: Removing Coolant Expansion Tank Bolt

Courtesy of AUDI OF AMERICA, INC.

Test for short between all three terminals in knock sensor connector (terminals 1+2, 1+3, 2+3).
- Specified value: INIFINITY Ω (no continuity) the wiring must not be connected to each other.
If there is a connection between terminals, install a new knock sensor.

Fig 3: Identifying Knock Sensor Connector Terminals

Courtesy of AUDI OF AMERICA, INC.

If no malfunction is found: