active bonnet malfunction error message

azimabdul1983

Member
Joined
Feb 13, 2018
Messages
11
Reaction score
2
Your Mercedes
E Class / 2010 / E200 CDi
It has only been just over one week since I purchased my car (E200 CDi Sport, 2010 model), on the drive back I noticed that the washer fluid was empty. When I got home I opened the hood and filled up the washer fluid as normal.

When I closed the bonnet the first time I noticed on the dash the red sign showing that the bonnet had not been closed properly even though from looking at it to me it seemed to close properly. In any case, I opened the bonnet again and closed it again but this time giving it a bit more force to close it. This time the red sign did not appear so was content that I had closed it properly.

Then three days later mid-way through a drive on a dual carriageway where I was probably doing around 50MPH a message appeared on the dash saying "active bonnet malfunction, see owners manual...". The message is intermittent as I drive to work daily and it has come and gone on and off.

Looking into the process to reset the active bonnet, my car has not hit anything and to my knowledge nothing has come into the car and opening the bonnet and looking at the top (near the windscreen) I can see that the active bonnet has not raised and the metal locks are in place. There was no need for me to push the bonnet back down as nothing happened and bonnet did not raise up. Again, when I closed the bonnet the first time and got back in the car the red sign on the dash showing the bonnet is not closed properly showed up again even though I know I closed the bonnet properly. So again, opened the bonnet and then closed again with a bit more force this time and the red message was gone.

Should I be worried at all, could it possibly be just a sensor / electrical glitch?
 

Ken_R

Senior Member
Joined
Dec 11, 2015
Messages
691
Reaction score
201
Location
Worcestershire, UK
Your Mercedes
W203 2006 C230 Estate
I'd be lubricating the bonnet locking mechanism and release cable end(s) with silicone grease

ae235


Somewhere there will also be a micro switch. Follow any wiring and check that it is securely held.
 
OP
azimabdul1983

azimabdul1983

Member
Joined
Feb 13, 2018
Messages
11
Reaction score
2
Your Mercedes
E Class / 2010 / E200 CDi
  • Thread Starter
  • Thread starter
  • #3
I'd be lubricating the bonnet locking mechanism and release cable end(s) with silicone grease

ae235


Somewhere there will also be a micro switch. Follow any wiring and check that it is securely held.

Thank you for the info, I will give that a try and see what happens. Since posting the message, the message has not shown up again but will give this a try in any case.
 

Headhurts

Senior Member
Joined
Jul 24, 2014
Messages
932
Reaction score
243
Location
Norwich, Norfolk
Your Mercedes
E350 Night Edition Estate/2016/Diesel
The bonnets do need a considerable amount of force to close them properly.

On mine I really have to give it some force, it was the same on my previous car and both were brand new so really not a lot of wear had occurred.

So as above apply lubricant and shut that bonnet with force.

Robin


Sent from my iPad using Tapatalk
 

Mr Filipov

Senior Member
Joined
Dec 31, 2015
Messages
730
Reaction score
148
Location
Huntingdon
Your Mercedes
2017 BMW 535d Gran Turismo
All 212s display the message about the bonnet not being shut when it is. Common trait apparently. Mine does it as well. Went to see a 64 plate one. Did it as well and the list goes on.
 

Submariner1

Senior Member
Joined
Sep 3, 2016
Messages
4,453
Reaction score
632
Location
Windsor Berkshire
Your Mercedes
CL500 2009 5.5
The bonnets do need a considerable amount of force to close them properly.

On mine I really have to give it some force, it was the same on my previous car and both were brand new so really not a lot of wear had occurred.

So as above apply lubricant and shut that bonnet with force.

Robin


Sent from my iPad using Tapatalk

All my SLs bought new shut nicely.
Do you drop them or push shut?
This CL needed a 4” drop sbove the catch touching.
Seemed a tad heavy handed.

So I adjusted...extended the U Brackets evenly. Very easy to do. Just mark with tape where it was in case u want to return it to the original position.

No you lower it till the long catch touches .. raise it 2” and let go.

No crashing drama, no heavy impact crash, just a nice clean “thud” and its fully locked, no rattles , looks the same gap difference all around.
Perfect.
 

Headhurts

Senior Member
Joined
Jul 24, 2014
Messages
932
Reaction score
243
Location
Norwich, Norfolk
Your Mercedes
E350 Night Edition Estate/2016/Diesel
All my SLs bought new shut nicely.
Do you drop them or push shut?
This CL needed a 4” drop sbove the catch touching.
Seemed a tad heavy handed.

So I adjusted...extended the U Brackets evenly. Very easy to do. Just mark with tape where it was in case u want to return it to the original position.

No you lower it till the long catch touches .. raise it 2” and let go.

No crashing drama, no heavy impact crash, just a nice clean “thud” and its fully locked, no rattles , looks the same gap difference all around.
Perfect.

My bonnet has gas struts or hydraulic that support the bonnet.

Once the catch is released it raises itself to the first level, I then push the bonnet up against resistance the rest of the way.

To close it you are pushing against a reasonable amount of resistance so yes a hefty closure is required, the bonnet would not drop shut of its own accord.

Robin


Sent from my iPad using Tapatalk
 

John Laidlaw

Senior Member
Joined
Nov 15, 2013
Messages
26,377
Reaction score
9,037
Location
Wirral
Your Mercedes
BMW 530d X Drive Tourer M Sports
Ditto^ lower it and then a firm push no drama
 

ajlsl600

Senior Member
Joined
Nov 18, 2013
Messages
5,494
Reaction score
2,707
Location
france
Your Mercedes
clk3202001,sl6002003 with everything regrettably sold ,A class 170cdi auto. NG/TF1800 ML250
my SL i just drop it from about a foot ,closes nicely , no complications to disturb me , i think aerodynamicaly the bonnet unlikely to to come up whilst moving along unless it pops up at speed ,where upon the wind WILL get under it and maybe wreck yr day. i guess if you have a gas strut or two to lift the bonnet matters could get much worse ,how on earth did we ever manage before this potential headache was fitted and what on earth was wrong with the previous method . i have never had the bonnet come up on my cars,i have had it open and get caught by the catch , whereupon i slow down, stop asap and make sure its closed .simples
 

Submariner1

Senior Member
Joined
Sep 3, 2016
Messages
4,453
Reaction score
632
Location
Windsor Berkshire
Your Mercedes
CL500 2009 5.5
My bonnet has gas struts or hydraulic that support the bonnet.

Once the catch is released it raises itself to the first level, I then push the bonnet up against resistance the rest of the way.

To close it you are pushing against a reasonable amount of resistance so yes a hefty closure is required, the bonnet would not drop shut of its own accord.

Robin


Sent from my iPad using Tapatalk
I see a new or different system for the E Class.
 

mersum1es

Senior Member
Joined
Sep 25, 2010
Messages
2,052
Reaction score
268
Location
Finland
Your Mercedes
W212/-09/350CDI, W219/-07/320CDI, EX:W220/-01/320CDI, EX:W211/-04/320CDI, EX:W210/-01/270CDI
malfunction of front crash sensors triggers bonnet fault message...

I have always dropped all my mercs bonnet... but I am driving oldies only.
 
Joined
Apr 10, 2018
Messages
1
Reaction score
0
Your Mercedes
SLK250 cdi 2014 2.1 and B200 sport 2017 2.1
Bonnet switch sensor units.jpg Bonnet switch sensor units 2.jpg
It has only been just over one week since I purchased my car (E200 CDi Sport, 2010 model), on the drive back I noticed that the washer fluid was empty. When I got home I opened the hood and filled up the washer fluid as normal.

When I closed the bonnet the first time I noticed on the dash the red sign showing that the bonnet had not been closed properly even though from looking at it to me it seemed to close properly. In any case, I opened the bonnet again and closed it again but this time giving it a bit more force to close it. This time the red sign did not appear so was content that I had closed it properly.

Then three days later mid-way through a drive on a dual carriageway where I was probably doing around 50MPH a message appeared on the dash saying "active bonnet malfunction, see owners manual...". The message is intermittent as I drive to work daily and it has come and gone on and off.

Looking into the process to reset the active bonnet, my car has not hit anything and to my knowledge nothing has come into the car and opening the bonnet and looking at the top (near the windscreen) I can see that the active bonnet has not raised and the metal locks are in place. There was no need for me to push the bonnet back down as nothing happened and bonnet did not raise up. Again, when I closed the bonnet the first time and got back in the car the red sign on the dash showing the bonnet is not closed properly showed up again even though I know I closed the bonnet properly. So again, opened the bonnet and then closed again with a bit more force this time and the red message was gone.

Should I be worried at all, could it possibly be just a sensor / electrical glitch?
Hi there,
New to forum today(Thanks guys!)
With regard to this bonnet warning, I can tell you that I had the same on my SLK 250 a while ago.
The problem was with the plugs to the bonnet switch units.
My car had previously been in a accident, however I was aware of this when I purchased the car and fixed it up.
There are 2 switches on the SLK model, one has a micro switch and a sensor(4 connection plug) and the other has just a sensor (2 connection plug)
You need to be sure that they are making a good connection, that there is no damage to the plugs and wiring and that the strikers are engaging with the switches correctly. I have included a photo upload of the switches, casings and mechanisms. Hope you getr sorted ok.
 
OP
azimabdul1983

azimabdul1983

Member
Joined
Feb 13, 2018
Messages
11
Reaction score
2
Your Mercedes
E Class / 2010 / E200 CDi
  • Thread Starter
  • Thread starter
  • #14
Thank you for the reply, I have not had the message come up anymore since my original post but the info is useful and will keep to mind if I get the message come up in future.

View attachment 42478 View attachment 42479
Hi there,
New to forum today(Thanks guys!)
With regard to this bonnet warning, I can tell you that I had the same on my SLK 250 a while ago.
The problem was with the plugs to the bonnet switch units.
My car had previously been in a accident, however I was aware of this when I purchased the car and fixed it up.
There are 2 switches on the SLK model, one has a micro switch and a sensor(4 connection plug) and the other has just a sensor (2 connection plug)
You need to be sure that they are making a good connection, that there is no damage to the plugs and wiring and that the strikers are engaging with the switches correctly. I have included a photo upload of the switches, casings and mechanisms. Hope you getr sorted ok.
 


ALL MBO Club members qualify for 15% discount on second hand parts.Please see MBO Members’ Area for discount codewww.dronsfields.com
Top Bottom