2014 ML350 Bluetec HVAC Lin 1 (U100887)
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2014 ML350 Bluetec HVAC Lin 1 (U100887)
HVAC blowing hot air. No control of flaps. Only code is "U100887 D00887 - LIN bus 1 has a malfunction, the message is missing".
Wiring looks ok. Connections behind AAC controller all look good. Taken apart and reattached.
Anybody have an idea how to test to see if this is a stepper motor failure or shorted LIN cable?
Any assistance appreciated!
Wiring looks ok. Connections behind AAC controller all look good. Taken apart and reattached.
Anybody have an idea how to test to see if this is a stepper motor failure or shorted LIN cable?
Any assistance appreciated!
Last edited by n505906; Dec 8, 2024 at 06:52 PM.
Newbie
Joined: Dec 2024
Posts: 3
Likes: 0
HVAC blowing hot air. No control of flaps. Only code is "U100887 D00887 - LIN bus 1 has a malfunction, the message is missing".
Wiring looks ok. Connections behind AAC controller all look good. Taken apart and reattached.
Anybody have an idea how to test to see if this is a stepper motor failure or shorted LIN cable?
Any assistance appreciated!
Wiring looks ok. Connections behind AAC controller all look good. Taken apart and reattached.
Anybody have an idea how to test to see if this is a stepper motor failure or shorted LIN cable?
Any assistance appreciated!
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
oxidized solderless pins...
99% chance your AAC module was built with nearly reliable pressed pins that got oxidized to become a poor connections.
-- Luckily this can quickly be soldered better than new with a basic AMZ soldering iron...
-- else you can troubleshoot the chassis until you know exactly where AAC LIN1 is connected then purchase new modules, get everything installed and coded...
Plan B: the flap actuators also feature the same solderless pins easily soldered as well.
See links in my signature where all this self-help is detailed.
-- Luckily this can quickly be soldered better than new with a basic AMZ soldering iron...
-- else you can troubleshoot the chassis until you know exactly where AAC LIN1 is connected then purchase new modules, get everything installed and coded...
Plan B: the flap actuators also feature the same solderless pins easily soldered as well.
See links in my signature where all this self-help is detailed.
Last edited by CaliBenzDriver; Jan 3, 2025 at 07:38 PM.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
If you have soldering skills, you can solder the marginal junctions under 10mn.
Follow this self-help link... AAC module is in there for ya.
Last edited by CaliBenzDriver; Jan 16, 2025 at 08:14 PM.
