ECU's not allowing A/C to turn on... need advise

[olsen185]

I recently took my car (1996 328i) took a repair shop to fix my air conditioning system that hasn't worked in a few years. The mechanic said that after hooking up the scan tool he realized that the ecu is not grounding the a/c compressor relay. He also said the he was able to activate all a/c related components via the scanner (GT1 I think), so he knows everything else is working properly. Of course he can't get into the ecu software because it is encrypted by AA.

Has anyone else heard or dealt with anything like this? I wrote an email to AA yesterday but I haven't heard back from Karl yet. Any advice is appreciated.

Erik

[gerry_miranda]

Let me know...since I had my AA chip in the car, the AC has not worked. Cant find the cause. I asked some folks but they said that its not touched by AA.

[Matt]

Interesting. I can't see doing that in software.

Are you sure you don't just have a bad pressure switch?

[olsen185]

I didn't do any of the trouble shooting so I really don't know about the preassure switch. The shop doing the work is a BMW/Audi/merc shop that said all ac related components are working. They can run the ac if they manually ground the ac compressor relay.

Btw where is the pressure switch you mention?

[Matt]

They are in the AC lines or the dryer.

Did they try using DIS to cycle the compressor through the ECU? It could be a wiring harness issue.

[olsen185]

They are in the AC lines or the dryer.

Did they try using DIS to cycle the compressor through the ECU? It could be a wiring harness issue.

Yes based on my conversations with them that is what they did. They said they were able to activate the components via computer and confirm that all else is working. Btw the shop is Autobahn, donovan's old shop.