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programing the heater control

5K views 9 replies 5 participants last post by  Roblw123 
#1 ·
Does any one know how to reprogram the heater control unit? I purchased a used one to replace the original because of bad pixels and now the car will not go into sleep mode.
I have reset the battery, but that did not fix it. (everything works, except for the sleep mode)
I looked thru the other forum threads but could not find any help. Is this stealership only?
 
#4 · (Edited)
Not sure why you'd need to replace the FSU if you weren't having an issue with the HVAC blower (either being erratic while running...or turning itself off/on even without the key in the ignition).

Where did you get your IHKA unit...and was it from an e39 or an e53? And is it exactly like the original IHKA (did the original have the REST button or the MAX button...and what does the replacement have)?

The pic below is the FSR/FSU (final stage resistor/final stage unit) which is a component of the HVAC system that controls & regulates the blower. The one on the left is the original resistor BMW used which was later changed to the one on the right. Since the newer unit has smaller & more cooling fins...some believe the high failure rate of the old style unit may have been from it's inability to shed heat fast enough:


The FSR/FSU is an oft discussed topic a common issue...so much that every BMW e39/e53 forum probably has a DIY or article in their FAQ forum about it...and I'm sure if you google "BMW E53 FSR/FSU" into a search box...you'll get more than enough info about it. :)

The e53 FSU is #3 in the diagram below:

 
#6 ·
the after market people keep insisting that the part # does not matter, if it fits it should work. i tried to get one as close to original as possible and found that to be very frustrating. The unit I ended up with looks the same, with all the same buttons, but the part # is different. (I found and paid for an exact match on ebay through German Audio Tech but they won't sent it to me!) I can't imagine BMW making different parts if they all work the same.
 
#7 ·
the after market people keep insisting that the part # does not matter, if it fits it should work....I can't imagine BMW making different parts if they all work the same.
Well...if you're going to hold on to that last statement...then prepare to have your mind blown into a million pieces because BMW does and will change a part nbr at the drop of a dime.

All it takes is to play around in the BMW ETK part databases and you'll see the word "ENDED" at the end of a row...where the next line below is usually the replacement. Sometimes you do have to look in the TO & FROM columns in case the part only functions for a specific build date range. Sometimes the new part is backwards compatible...and sometimes it' s not.

Certain parts that expand across multiple models and through multiple years...the nbrs will change especially if new features are added. For example, the e38 & e39 share the same front seats...so they also use the same control modules. The build date range for these 2 models runs between the end of 1994 thru 2003...that's almost a decade. And new features were added (like the convenience exit feature (around the 1998 model year)...and the new modules were backwards compatible.

If you click the following link (below) to bmwfans.info's part database site...if you move your cursor to the right of the 11 digit part nbr (for item #1)...you should see a blue "i" appear which will link you to the previous "ended" part nbr. Continue to click on the blue "i" until you don't get anymore old numbers...and you'll see how many different BMW part nbrs there are for the IHKA control panel. I used my 12/2005 build date to look up the part. You'll also see as you continue to click back that the site gives the date range that the particular BMW part nbr was used:

 
#9 ·
My FSR/FSU was responsible for killing my new battery and not letting the car go into sleep mode. Replacing it fixed all of that. Thankfully the bayyery was under warranty, and the dealer replaced it gratis.

There are is lots of guidance on replacing it. It is accessed from the passenger side behind the firewall up under the dash, sort of.
 
#10 ·
I have a 2005 X5 with the climate control for the rear. Recently my entire climate control system stopped working completely. No lights on, no blower, nothing. I purchased online a replacement control module and removed the old one. The replacement fits but an error message appears on the screen. I'm assuming it needs to be programmed to work in a different vehicle from which it came out of. So how do you program the replacement to work in my X5 ?
 
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