Climate Control troubles (again)

[Dag Bøsterud]

As I've stated in earlier mails to this mailing list, I have some rather strange misbehavior in the electronic climate control (ECC) of my
1990 Audi 100 TQ Sport.

The problem is as follows:
- The ECC is very fond of blowing hot air, also through the centre vents.
- A few times I haven't been able to regulate the temperature at all! The digits on the display have gone all the way from LO to HI,
but no change in temperature.
- A couple of times I have had to set the ECC to 28-29 C or HI to get any hot air out of it at all.

Until a couple of days ago I haven't been able to get any fault codes out of the system. The system just didn't report any fault codes.
I sure know how to get them out.
The fault codes (on channel 01) are as follows:
07 - Motor for positioning heater flaps in programmer NOT OK
15 - High pressure sensor - short circuit
The strange thing is that the fault code indicator lamp doesn't always light up when I start the engine, 
and If I'm not quick of the mark and read them when it lights up I get no fault codes... I find that strange.
..but then again, I don't know all that much about these things :p

Anyhow, fault code 07 appears to be the culprit to my temperature regulating problems.
Fault code 15, is that a "wear and tear" thing to the sensor/switch, it is malfunctioning?
Or could it be the wiring?

/Dag
1990 Audi 100 Turbo Quattro Sport Exklusiv