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-   -   All BMWs IHKA 801222 - missing DDE/DME release - potential solution (https://www.bimmerfest.com/forums/showthread.php?t=1350371)

Breach 10-11-2019 12:12 PM

IHKA 801222 - missing DDE/DME release - potential solution
 
I'm posting this to save other folks from wasting time. For couple of years now my car has been constantly logging this error in the IHKA ECU:

801222 - Air conditioning compressor: switch off due to missing DDE/DME release

No other symptoms, and that's not even a fault - it's an info event. But I'm anal about these things, so it was quite annoying.

Normally, this fault indicates that DDE/DME did not allow the AC compressor to run because of engine load - temperature conditions, etc. In my case, I was getting this error even with a cold engine start, so the description didn't make any sense. I did a lot of googling but no solution - many people say it's normal, many cars have it, etc.

I think I fixed it, at least in my case ;-) I was having nothing better to do, so I was browsing through TIS and noticed that after IHKA programming/encoding the Steering Wheel Normalization ABL has to be executed. What does IHKA have to do with the steering wheel you may ask? No idea. Did I program/encode IHKA via e-Sys, thus not running the post operations ISTA would? Yes I did. So, i ran the service function and no error for more than a week now! Thus, I am 99% sure it's fixed, as I was getting the fault instantly before.

Of course, in other cases it may be an actual AC problem, just sharing my experience.

Hope that's useful to someone.

Georgioso 01-24-2020 06:30 AM

What did you service exactly? I Could not find it in ISTA. Did normalize the (Electric) steering Wheel position but that did not solve my error ***x1f609;

Doug Huffman 01-24-2020 06:37 AM

Quote:

Originally Posted by Breach (Post 13130443)
801222 - Air conditioning compressor: switch off due to missing DDE/DME release

Normally, this fault indicates that DDE/DME did not allow the AC compressor to run because of engine load - temperature conditions, etc.

A/C Compressor Control

The IHKA is the master for controlling the A/C compressor. Pressing the AC button on
the air conditioning system operating unit switches the air conditioning system to the
ready state.The IHKA transmits a speed increase request to the DME (ECM).

Depending on the temperature and the nominal-value setting, the IHKA sends a cooling
power request to the DME (ECM) If the DME (ECM) is ready and in a position to provide
a torque of > 20 Nm, the DME (ECM) issues a release for a load connection of up to 30
Nm. This release is also monitored by the junction box. The IHKA issues a command to
the junction box to couple the connection. ...


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