Loud noise driver's side door, now clunking when opening
Thread Starter
Member
Joined: Sep 2014
Posts: 75
Likes: 8
From: SF Bay Area, CA
2016 E-350
Loud noise driver's side door, now clunking when opening
Hello all, I had an issue recently while driving home. I closed my driver's side front window, and heard a VERY loud thunk come from the door. It sounded like someone had thrown a rock at my door.
I pulled over and checked but didn't find any issue, but when I rolled down the window, I heard what sounded like a piece of plastic falling down inside my door, figured "oh great what broke"?
Now when I open the window, I hear a clunk come from the rear of the window, but it rolls up/down w/o any issues.
The door rolls up but I notice the motor seems to keep trying to close the window once it's all the way up.
I wonder if anyone has experienced this? I figure I'm probably going to have to take the door apart to see what ultimately broke.
@konigstiger do you have the instructions on this for 2016 ?
Thanks all for your help.
I pulled over and checked but didn't find any issue, but when I rolled down the window, I heard what sounded like a piece of plastic falling down inside my door, figured "oh great what broke"?
Now when I open the window, I hear a clunk come from the rear of the window, but it rolls up/down w/o any issues.
The door rolls up but I notice the motor seems to keep trying to close the window once it's all the way up.
I wonder if anyone has experienced this? I figure I'm probably going to have to take the door apart to see what ultimately broke.
@konigstiger do you have the instructions on this for 2016 ?
Thanks all for your help.
Out Of Control!!
Joined: Apr 2019
Posts: 11,922
Likes: 6,775
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
help yourself to STATUS data
Use a scanner to read the STATUS of your window control. You'll find that under "Body controls: DCU modules: Front-Left".
The way the window motor keeps trying to close the window even it is up already is ultimately what broke one of the plastic guides.
Use your passenger side to compare value or check for the same problem.
> Normalization :
These simple window motors are stateless (unlike seats)... the controller is what decides the measured peak current means "stopped". This process is called normalization. The window position between the up/down limits is always unknown.
The window travel auto-reversing at top/bottom is a clue the system has denormalized itself.
I am going to guess...
Your broken window guide issue was caused by the pressed-pins DCU module gone wild ie. don't just fix the window guide alone. Check/test the controller is smart enough to do its job of current control to stop or reverse window.
> Hands-on:
I just got done yesterday dealing with this very same driver side window motor control. I had flipped the armature magnets around and my window kept working the opposite way... then "Denormalized" itself crazy .... LoL.
The motor has an internal circuit board with a basic current sensing transistor logic that signals the Relay control in the door control module.
These tiny ROHS solders under high currents were not the best looking but not gone disconnected either. Since I was in there fixing all button modules in my door panel, I reworked the silly motor electronics for good measure.
The way the window motor keeps trying to close the window even it is up already is ultimately what broke one of the plastic guides.
Use your passenger side to compare value or check for the same problem.
> Normalization :
These simple window motors are stateless (unlike seats)... the controller is what decides the measured peak current means "stopped". This process is called normalization. The window position between the up/down limits is always unknown.
The window travel auto-reversing at top/bottom is a clue the system has denormalized itself.
I am going to guess...
Your broken window guide issue was caused by the pressed-pins DCU module gone wild ie. don't just fix the window guide alone. Check/test the controller is smart enough to do its job of current control to stop or reverse window.
> Hands-on:
I just got done yesterday dealing with this very same driver side window motor control. I had flipped the armature magnets around and my window kept working the opposite way... then "Denormalized" itself crazy .... LoL.
The motor has an internal circuit board with a basic current sensing transistor logic that signals the Relay control in the door control module.
These tiny ROHS solders under high currents were not the best looking but not gone disconnected either. Since I was in there fixing all button modules in my door panel, I reworked the silly motor electronics for good measure.
Last edited by CaliBenzDriver; Mar 26, 2022 at 02:58 PM.
Out Of Control!!
Joined: Apr 2019
Posts: 11,922
Likes: 6,775
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
from Window to central locking.... DCU ??
Your scanner reads "historic" meaning stored ie. it's not current?
Take a look at the live data section for windows status. The absence of Window active fault does not mean it is A-Ok!
Have a closer look at your door control module circuit board. Are the pressed-pin looking bright or dark & discolored from heat?
Snap couple good pics if u need help.
The front DCU location as seen on passenger side.
This unassuming small module is in charge of the whole door interface (mirror, window, lock, seat position, lateral acceleration, illumination, door ajar,...) with countless other busy networked controllers. The potential trouble here is there are 4x DCU.
Here is the front window motor:
Built-in basic 5-wire logic. Screw drive needs lube
> Mfg playing games:
This "Brose" German motor brand is using the same economy lube job as Bosch cabin blower motor.
I can see pieces of brushes contaminating the collector ring area. Normally you expect fine dust, here are chunks of soft carbon brushes burned with high currents.
As for simple remedial, I've oiled the motor spinning bearing surfaces and high-temp silicone greased the screw drives and both shaft ends. Then soldered and coated the motor tiny electronic circuit.
Last edited by CaliBenzDriver; Mar 29, 2022 at 11:47 AM.
