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 location overview Page 24-5

Note:

The engine speed sender is a combined speed sender and reference mark sender. The engine cannot be started without a signal from the -G28 engine speed sender. If the signal from the -G28 engine speed sender fails while the engine is running, the engine will cut out immediately.

Test sequence

• ‒ Before carrying out the test, make sure that the sender is correctly installed and firmly seated.

• ‒ → Detach connector of engine speed sender -G28 -Pos. 3- in engine compartment.

Note:

To gain access to the connector screw out coolant expansion tank bolts and swivel expansion tank aside. Fuel hoses remain connected.

• ‒ → Connect multimeter between contacts 2 and 3 to measure resistance.
• ‒ Specified value: 730...1000 ω

Note:

The resistance figure for the engine speed sender is associated with a temperature of 20 °C. The resistance increases with increasing temperature.

If specified value is not attained:

• ‒ Fit a new engine speed sender.

If specified value is attained:

• ‒ → Connect multimeter between contacts 2 and 1 (screen) and 3 and 1 (screen) to measure resistance.
• ‒ Specified value: each case ∞ ω (no continuity)

If specified value is not attained:

• ‒ Fit a new engine speed sender.

If specified value is attained:

• ‒ Connect the V.A.G 1598/31 test box to wiring harness leading to engine control unit; the engine control unit should not be connected .

• ‒ → Check for open circuit and short to positive or earth in the following wiring connections:

• ‒ Rectify any open/short circuit as necessary.

If no wiring fault is detected:

• ‒ Fit a new engine control unit => Page 24-23.