Audi Workshop Service and Repair Manuals

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select the engine electronics control unit using "Address word" 01. When doing this the engine must be running at idling speed.
  (Connecting fault reader and selecting engine electronics control unit .)

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

• ‒ Press keys 0, 0 and 7 for "display group number 7" and confirm entry with Q key.

• ‒ Check display in display zone 4 (coolant temperature).

• Specified value: The temperature reading should increase at a uniform rate.

If there is a fault, the fuel temperature will be displayed as a substitute value (display zone 1).

If an implausible value is displayed in display zone 4, or if the fuel temperature is displayed as a substitute value:

• ‒ Switch ignition off.

• ‒ → Pull off the connector on the sensor => Overview of fitting locations, Page 23-4.
• ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit .

The following wiring connections are to be checked for open circuits and/or short to positive or negative.

• ‒ Rectify any open/short circuit as necessary.

=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder

If no wiring fault is detected:

• ‒ Replace coolant temperature sender (G62).