Affected vehicles: 2005-’08 A6
Condition: With the same temperature settings, different temperature air comes
from the outlet vents on the driver side and passenger side. The outside outlet
vents release warm air, and the inside outlet vents release cool air.
Technical Background: Debris remaining inside the engine block during
production blocks the pump valve unit. As a result, one valve can stay
permanently open, allowing warm coolant to flow into one of the heat
exchangers. Other factors may be the electrical connector is not seated
completely or the pin is pressed out; the outside temperature sensor G17 shows
incorrect value; and/or the pump valve unit is faulty.
Service:
1. Turn both sides on Low. If the temperatures on the driver and passenger
sides do not clearly drop to a reasonably equal temperature (one side is warmer
than the other), a valve in the pump valve unit is blocked. Replace the pump
valve unit.
2. Check the electrical connector on the pump valve unit in the plenum chamber
(Fig. 1). Seat the plug correctly, or repair the pin with repair case VAS
1978A.
3. If the VIN is between 4F_5N065500 and 4F_6N026537, complete the procedure in
TSB 2010148, Outside Temperature Display Too Low, Air Conditioning Undefined.
4. Turn both sides on Low. If the temperatures on the driver and passenger
sides are hot and remain so, cycle the ignition key off, then on. If the
condition is corrected merely from the key cycle, replace the pump valve unit
with P/N 4F1 959 617B.
Tip: Do not replace the display and operating unit for the climate control
system, as this will not resolve this condition.
Courtesy of Mitchell 1.
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