Audi Workshop Service and Repair Manuals

Fitting location => Fitting locations overview, Page 23-4

Test requirement:

• ● Engine cold

Test sequence

• ‒ Read data block, Display group 007, engine cold and running at idling speed=>Page 01-131

→ Display on VAS 5051:

• ‒ Check readout in display zone -4-.
• ‒ Specification: The temperature value should increase steadily.

Note:

In case of a fault, the fuel temperature will be displayed.

If the fuel temperature display is defective as well, a constant temperature of -5.4°C will be displayed.

• ‒ Press the ◂ button to exit from the function "08 - Read data block".
• ‒ Select diagnosis function "06 - End output".
• ‒ Switch off ignition.

If an implausible value is displayed in display zone 4:

Testing internal resistance

• ‒ Unplug 4 pin connector from coolant temperature sender G62.
• ‒ → Connect multimeter (resistance test range) between contacts C and D on the sender.

Scale A shows resistance values for temperature range 0...50 °C and scale B the values for temperature range 50...100 °C.

→ Examples:

• ◆ 30 °C corresponds to a resistance from 1500...2000 ω
• ◆ 80 °C corresponds to a resistance from 275...375 ω

If the specification is not attained:

• ‒ Fit a new coolant temperature sender.

If the specification is obtained:

Checking wiring connections

• ‒ Connect test box V.A.G 1598/31 to wiring harness for engine control unit.Do notconnect to the engine control unit itself:
• ‒ Connecting test box to engine control unit without protective housing=>Page 23-49.
• ‒ Connecting test box to engine control unit with protective housing=>Page 23-51.

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

• ‒ Test for short circuits between the two wires.
• ‒ Rectify any open/short circuit as necessary.

If no fault is found:

• ‒ Replace engine control unit
• ‒ Removing and installing engine control unit without protective housing=>Page 23-57.
• ‒ Removing and installing engine control unit with protective housing=>Page 23-60.