Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

• ◆ V.A.G 1526 A
• ◆ V.A.G 1594 A
• ◆ V.A.G 1598/31

Fitting location => Fitting locations overview, Page 24-5

Notes:

• ◆ It is not possible to carry out an electrical test of the knock sensors themselves (-G61 and -G66).
• ◆ Always use gold-plated contacts when repairing the knock sensor connectors.
• ◆ To ensure that the knock sensors function properly it is important to keep exactly to the specified tightening torque of 20 Nm.
• ◆ Check for corrosion in connection between knock sensor and wiring harness.

Testing knock sensors

• ‒ Unplug the connector for the relevant knock sensor in the engine compartment.

• ‒ → Test for short circuits between all three contacts in the knock sensor connector (contacts 1+2, 1+3 and 2+3).
• ‒ Specification: ∞ ω (no continuity) - there must be no connection between any of the contacts.
• ‒ If there is a connection between the contacts, fit a new knock sensor.
• ‒ If there is no short circuit, test wiring for knock sensors.

Testing wiring between knock sensors and engine control unit

• ‒ Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
  .
• ‒ Test for open circuit and short to positive or earth in the following wiring connections:

• ● → Knock sensor 1 -G61 (cylinders 1/2)

• ● Knock sensor 2 -G66 (cylinders 3/4)

• ‒ Rectify any open/short circuit as necessary.