climate control pixels

[Tomdownunder]

My climate control has a few dodgy pixels. The unit itself looks almost identical to to the one on my E39 except for the button which says "MAX". This was used as "REST" on the E39 which is for blowing hot air from around the exhaust manifold when the car is parked so it is still warm when you get back in after shopping or something on a cold day.

On the ETK they are 2 different part numbers. Anyone know if they are interchangeable and if so will the "rest" button become a "max" button. Or alternatively, how easy is it to change display.

I am going to sell the E39 and want to know if I should do some parts swapping first or whether the pixel repair is a cheap/relatively straight forward fix. E39 is 1997 528i touring, X5 is 2004 3.0 diesel.

[ndz]

Hi Tom. I can only speak for my e39 but I swapped my IHKA (intermittent heat failures, probably capacitors) a few weeks ago and this was my experience:

For e39's you don't have to re-code the IHKA if you buy the one with the same button (REST or MAX). I haven't heard of anyone swapping to/from and e53 though so you should verify. You could check the part numbers for different years on RealOEM and see how they compare.

In the 99 model year they deprecated the old IHKA and had a new part number for the same "REST" version. I picked up a used one on Ebay for $100USD. I wouldn't expect a used one to cost much more than that even in Oz. Maybe less at a pick and pull.

If you find a way to just fix the pixels, even better. Let us know what you find out.

[Qsilver7]

The IHKA with the REST feature are not the same as the ones with the MAX feature.

The IHKAs with MAX have additional programming and functions...that the ones with REST do not have.

As mentioned, the REST feature allows you to blow warmed air into the cabin (even with the key removed from the ignition) for up to 30 minutes if the ambient temps are below 59° F.

The IHKAs with the MAX button can still do the REST feature (all the same conditions apply)...but also have programming for closing the fresh air flap and turning the blower up to maximum speed when ambient temps are above 61° F...and it also has an extra connection to a solar sensor that was added during the same time.

If you try to upgrade from REST to MAX and your build date is near the time MAX came online...you may have the software to run the IHKA w/MAX...but you still don't have all the accoutrements (the solar sensor). If you have an older build date (ie 97/98) and you upgrade to the MAX IHKA...you may need to have some coding done due to different software requirements.

(IHKA w/MAX has both REST features and MAX features as well as can take data from the solar sensor)


(IHKA w/REST only has REST features....& there's no solar sensor installed in the car to perform duties the MAX IHKA would in certain conditions)

[Tomdownunder]

Thanks for the response, I am going to have a look at both units when I have some days off and see if it is possible to swap displays as the E39 display is perfect even though it is 7 years older and the vehicle has double the mileage of the E53. The other issue with the E53 is that the max button has a corner missing out of it (like someone tried to get it off and broke it) so I will have to try and source another button or do some very clever fixing and shaping with JB weld and some black paint. I have seen sets of buttons on ebay, but not individual buttons.

[Qsilver7]

Here is a vendor that sells individual IHKA buttons: IHKAButtons.com

EDIT: oops....forgot you're not in the USA...but you can still check out the site linked above...they have instructions on how to remove/install the buttons etc.