Audi Workshop Service and Repair Manuals

Test sequence

• ‒ Read data block, Display group 007, engine cold and not running=>Page01-131

→ Display on VAS 5051:

• ‒ Check readouts in display zones -1-, -3- and -4-.
• ‒ Specification: All temperature values approx. the same
• ‒ 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 3 (substitute value if fault occurs: 135.9 °C):

Testing internal resistance

• ‒ Remove windscreen washer fluid reservoir.
• ‒ → Unplug connector at intake manifold temperature sender -G72 (in charge air cooler) -arrow-.

• ‒ → Connect multimeter between contacts 1 and 2 of sender (resistance measurement range).

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 obtained:

• ‒ Renew intake manifold pressure sender with intake manifold 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 all wires for short circuits with each other.
• ‒ 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.