2002 4.6is climate control problem!

[x5Alpine]

Hi, my 02 4.6is has had an extremely annoying problem with the climate control since I bought it in Feb. The air-con works perfectly but when I turn the heater on and after it's been on for around 2 minutes the whole climate control screen Shuts itself off but the heater still runs but then I can't Shute it off. My Indy has replaced the whole unit twice! And the FSR, it's seriously driving me insane because I can't figure out at all what it could be.

Thanks!!

[Qsilver7]

Some questions:
1. can you describe what you mean by "turn the heat on"? I ask because...if you have the auto IHKA control unit...the system's default is that it's always on...and the system keeps the cabin at the TEMP you have set. The AC has it's "snowflake" button that engages the AC compressor which dehumidifies the air in the summer and on those fall/spring days that are cool (above 41 °F) yet humid enough to cause condensation to build up inside the cabin's windows...but there's nothing that really turns the "heat" on except the system adjusting itself to keep the TEMP set on the display versus the ambient temp outside the vehicle. So just need clarification as to what you mean by "turn the heat on".

2. When your "indy" replaced the IHKA control unit...did they "code" it to your X5? I ask that because there are multiple units that can fit (one has a REST button & the other has a MAX button). If the software required to run the IHKA control panel is different that what your X5 has...it can cause operating issues with the unit.

3. Do you know which FSR was used when replaced? If the updated FSR wasn't used...then you can continue to have the same issue:

old style (faulty) FSR on the left...vs...new style (updated w/more cooling fins) FSR on the right

[x5Alpine]

When I say turn on the heater I mean by turning up the temp on both zones to 90 and moving the wheel on the vents to the tree red dots. He told me he coded it to the X and the fsr is the updated one.

[Qsilver7]

Why do you increase the temp setting to 90°F? If you select a temp that is comfortable for you (let's say 72°F)...the temp inside the cabin doesn't warm up to that temperature any faster by changing the temp setting to 90°... the auto IHKA control panel (if set to AUTO + AUTO fan speed)...will do what it takes to get the cabin temp to 72° ASAP. Your X5 is equipped with an "auto" climate control system...there's really no need to make wide temp adjustments to keep the cabin comfortable. It's much like the thermostat in your home's HVAC system.

But back to your issue at hand...what happens if you set a temp that's comfortable for you and let the IHKA control panel alone...set the stratified air dial centered...or only 1-2 dots into the red...and keep everything in the AUTO setting (air direction & fan speed) and only use the AC/snowflake button (if necessary to dehumidify the air)...does it still shut itself off or have the same symptoms you described in the first post?

[x5Alpine]

If I hit the snowflake button the thing works just fine but when I crank up the temperature on the IHKA then that's when the whole display shuts itself down after a few minutes then once in a while flickers on and off. BTW, thankyou so muchfor your help!

[Qsilver7]

Hmm, thanks for the clarification. I wish I had better answers...especially as to why the IHKA shuts down if you crank the TEMP up to 90. It shouldn't do this...so there is obviously something wonky going on.

It would be odd to have multiple IHKA control units do the same thing...but it could happen if the replacement is a used IHKA unit (even though I'm still leery as to if coding is being done correctly...not being there seeing what is being coded leaves me room for skepticism).

Until more can be figured out...I'd try to avoid adjusting the Temp upward/downward...just select a comfortable temp and leave it there...make any adjustments by using the stratified air dial (in the middle of the dash's center vent)...and the AC/snowflake button if you need to cool and or dehumidify the air if ambient temps get warmer or the air get's heavy with moisture & condensation starts fogging up the glass.

[x5Alpine]

My Indy did mention that the IHKA is a rebuilt one from bill pearce BMW here in Reno. He's going to replace the ignition switch but would that do it?

[Qsilver7]

Originally Posted by x5Alpine

...He's going to replace the ignition switch but would that do it?

Hmm, that's interesting, too. His thinking may be from the odd electrical gremlins that can occur when the ignition switch begins to fails. You can get no start situations, as well as odd seemingly unrelated electrical gremlins like steering wheel moves on its own, radio shuts off & on by itself, horn stops working, Air bag light illuminates but there's no fault codes, etc.

See the videos below and a trick that can sometimes replicate the odd electrical gremlins. Start the engine, then turn on the radio, lower the passenger sun visor and open the mirror's cover and if odd electrical gremlins start happening...this is usually the ignition switch:

(signs of a failing ignition switch)

Signs of Failing Ignition Switch in BMW e38 7 series or e39 5 series - YouTube

(replaced ignition switch & symptoms went away)

BMW E38 Fixed Ignition Switch Electrical Gremlins Disappear - YouTube

To be honest, I don't have high hopes of this being the issue...but...you never know...

[x5Alpine]

I'll have to try that...my car a few times when I try and start it with the start assist just cranks and doesn't stop until I shit it off, then it starts right up 2nd try. Only happened 3 times.

[x5Alpine]

OK, so my indy has replaced the IHKA 3 times, the ignition switch, and the FSR. The heater is still doing the same thing and its driving me insane!, tonight while driving home I got to the point of punching the stupid IHKA from pure frustration. Please HELP!!