Audi Workshop Service and Repair Manuals

Notes:

• ◆ For testing the operation of the knock sensors, see "Reading measured value block", Display Groups 14, 15, 16 and 17.
• ◆ Fitting locations of plug connectors and knock sensors .
• ◆ It is not possible to carry out an electrical test of the knock sensors themselves; (interrogate fault memory
  ).
• ◆ To ensure that the knock sensors function properly it is important to keep exactly to the specified tightening torque of 20 Nm.
• ◆ Check connectors for corrosion.
• ◆ Use only gold plated contacts when repairing the contacts in the plug connectors for the knock sensors.

Testing knock sensor wiring

• ‒ Unplug knock sensor connector in engine compartment.
• ‒ → Test for short circuits between all three contacts in the knock sensor connector. The must be no connection between any of the wires.
• ‒ If there is a connection between the contacts, fit a new knock sensor.

Testing wiring from knock sensors to engine control unit

• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
  .
• ‒ Test for open circuit and for short to positive/earth or between wires in the wiring between the knock sensor and engine control unit using the current flow diagram.

=> Current Flow Diagrams, Electrical Fault Finding and Fitting Locations

• → Identification of contacts in plug connector:

• ‒ Test continuity of signal wire of knock sensor 1 -G61 from contact 1 on connector in engine compartment to socket 68 on test box.

Specification: max. 1 ω.

• ‒ Test continuity of earth wire of knock sensor 1 -G61 from contact 2 on connector in engine compartment to socket 67 on test box.

Specification: max. 1 ω.

• ‒ Test continuity of screening on wiring for knock sensor 1 -G61 from contact 3 on connector in engine compartment to socket 67 on test box.

Specification: max. 1 ω.

• ‒ → If the values do not match the specifications, rectify the short circuits or open circuits.

• ● → Knock sensor 1