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IHKA Issue

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I'll start by saying I have searched the forums on this till I am bleary eyed. I purchased this roadster in Oct 2011, drove for a bit, and then put it away for the winter in my garage. When I pulled it out in the spring, it had this problem:

1) My blower will only blow at low speed
2) My A/C button is dead, so I can't run the A/C
3) The MAX A/C button is live, but pressing it does nothing
4) The AUTO button is also live, but pressing it only disables the fan
5) Rear Window Defogger button is also dead
6) The Auto Recirc. button is live and appears to work
7) The Max Defrost button is live but does nothing
8) Temp selection and air distribution dials work

So, the non-functioning items are fan speed (beyond low), rear defog, and A/C, therefore I suspect something cooked around the central part of the P/C board. Since three different functions are affected, I can't see it being something downstream of the IHKA control module.
I lived with it for the summer, as I usually had the top down anyway. But, now that it is getting cooler, I really need to have the front and rear defog. available

I expect I will be compelled to replace the IHKA module and get it programmed, unless someone has some other ideas?


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It also sounds like your car went in transport mode. Was it hard to start when you got it started ?

Dealer will need to reset it. It happens when the voltage on the battery gets too low, usually winter = a battery trickle or fully disconnect the battery.

Happen to me the first year, i end up disconnecting the battery fully last winter.
Thanks for the rapid response! The transport mode function would explain the phenomenon. I did run the car a few times in the winter, and at one point the battery was too low for a start. At this point I decided to keep it hooked up to a battery tender. Hopefully a simple re-set will do the trick!


After looking at some more convenient options, I finally broke down and headed for my 'local' dealership (a little more than an hour away). Anyway, once I spoke to the service manager he knew right away it was the "Transport Mode". The reset cost about $75 after taxes. Oh well. It seems that Transport Mode kicking-in when the battery gets low is more or less a Z4 exclusive 'feature'.
On the plus side, everything works and any excuse to drive the car is a good one! (I hadn't had it out of the garage for a while due to inclement weather)

Again, thanks to everyone for the input.

That sucks how they charge you for it. Anyway winter is coming up, either you put the battery tender on it for the winter or just unplug the battery. I unpluged my battery completely and it did not go into transport mode. Will be doing the same this winter if I dont drive it.
Yeah, I think anybody else would consider this to be a factory defect or recall item. It would be nice if BMW would step-up in this regard!
I started a battery tender last winter, but too late, I'm afraid. When you unplug your battery, I guess you first open the trunk to allow access and then wait for sleep mode to kick-in?
On my old Buick I fog the engine for the winter and pull the battery. With the Bimmer, I can't fog it and therefore like to run it every now and again, which is why I prefer to keep the battery hooked-up.
I just unplug a fully charged battery. If the voltage goes down it'll kick back into transport mode.
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