Electrical Meltdown

[oilburner]

I've been having various electrical issues with my 1998 w202.

First the drivers electric window stopped working...then the passenger. I changed the fuses and they were fine. Then the windows broke again. I pulled out the old fuses, tested then and they were fine. I replaced them and the indows worked again. This pattern has continued for some weeks now.

During that time the alarm has been going off in the night (possibly coincidental as the disable button the dash seems ot have cured this)

Then the infra red remote key stopped working on the drivers door. Today it has stopped working on the passenger door and I can't get into the car without the alarm going off.

Does anybody have any ideas on what may be causing this and any possible solutions? I'm begining to get rather frustarted and I forsee large bills!

Thanks as always

 

[stevesey]

Have you checked the battery voltage (both when stopped and with the engine runnng).

 

[oilburner]

Have you checked the battery voltage (both when stopped and with the engine runnng).

I haven't, do you think it might just be a failing battery?

The indicators and windscreen wiper have now stopped working. I noticed when changing the myriad of fuses that a lot of the systems that have failed, share fuses (which makes sense as far as them failing together). I wondered if it was an ECU problem but I'm no auto-electrician.

 

[stevesey]

Given the myriad of symptoms there is one thing all these share in common. And I'm aware that others have had similar issues/symptoms across several systems, which have turned out to be a failing battery.

Also, while you are there, as well as checking the voltage directly across the battery - check from +ve to body and the +ve side of a fuse to body to eliminate earth or +ve lead connections.

Equally it could be the one of the door controllers going down - I'm sure there was a member a while back who had a similar fault that spread to the other doors - possible if it took the CAN bus out (taking the fuses out would give the door controller a hard re-boot).

 

[oilburner]

Ok, I'll look into all that. Cheers Steve.

 

[Chattonmill]

I have the same issue with a door controller, the left hand one keeps on going down. Removing and reinserting the fuse seems to sort it out temporarily, but it always goes again. I am just living with it for now, not a major issue TBH.

 

[oilburner]

I have the same issue with a door controller, the left hand one keeps on going down. Removing and reinserting the fuse seems to sort it out temporarily, but it always goes again. I am just living with it for now, not a major issue TBH.

That's what I thought until everything else started to go west.

I haven't checked the battery yet (don't have the kit currently) but doesn't the fact that the car is starting fine mean the battery is ok?

 

[alexander patie]

door modules

hello all, some help with the window problem.

w202 and some w210 cars suffer failing REAR door controllers. although they continue to work they 'knock out' the low speed can bus.

one of the effects is to cause one or both front modules to shut down on the can bus, when connected to star no communication is possible. disconnecting the power supply and then reconnecting usually 're-boots' the front module/s - for a while.

this problem is easy to diagnose with star, just a quick can test in the ezs, backed up by checking live data while disconnecting the can wires to the rear modules.

without and special equipment you can diagnose, just a little more awkward. remove the n/s sill trim with a flat screwdriver. open the plastic duct and find the can bus connector near the front of this aperture. it is a black plastic strip with several plugs all connected in parallel, all the wire pairs are brown and brown with red trace. disconnect the plugs one at a time, test rear windows, and isolate can wires to rear windows (ie when the window stops working you have isolated it's can plug). mark the two plugs so you know which side is which.

now you have found the can wiring connections to the rear windows, leave them both disconnected and enjoy using your windows until you feel that i was definitely right and you want to know which rear window controller to change.

now plug ONE back in. use the car like this until the front windows fail, or you feel they have had chance to and will not. if they fail change that side REAR window controller. if they don't, unplug that good side and connect the one you have not tried yet and repeat the testing over time process.

i have seen this scenario several times myself now, so can be fairly certain of my advice.

 

[oilburner]

Thanks for all the helpful advice with this. I'm going to have a bash at these Door Control Modules. I've never had a car with side airbags though. If I open up the door panels in the front doors is there anything I have to watch out for as far as settting the airbags off, or anything else for that matter?

 

[alexander patie]

not sure what you are going to do with the front door control modules? i have not suggested they are at fault.

the easiest way to diagnose which side REAR controller is at fault is as i suggested. the sill trim is visible in the bottom of the front door opening when the door is open - you know, that plastic trim that often gets stepped on when you get in/out?

 

[oilburner]

not sure what you are going to do with the front door control modules? i have not suggested they are at fault.

the easiest way to diagnose which side REAR controller is at fault is as i suggested. the sill trim is visible in the bottom of the front door opening when the door is open - you know, that plastic trim that often gets stepped on when you get in/out?

Sure, but if the door cards do have to come off is there any risk of setting off the airbags?

 

[nick mercedes]

Sure, but if the door cards do have to come off is there any risk of setting off the airbags?

None.

 

[wemorgan]

Just ensure that the key is not in the ignition.

 

[alexander patie]

do not remove the front door cards as THERE IS NOTHING WRONG WITH YOUR FRONT DOOR CONTROL MODULES.

they stop working - sure - but the problem is to do with the rear modules causing the fronts to stop working. also other systems on the interior can bus such as the pse module (locking and alarm)

if you try my methods outlined in a previous and thorough post, you will get a cure. for free if you can cope without the use of a rear electric window.

no, the airbags will not go off either. removing front door cards is safe as they are not joined to them. airbags generally are extremely difficult to activate without driving into a tree or similar. however you have no need to remove the front ones, and can avoid removing the rear ones if you like (again, see previous post)

 

[Mohnish]

I had a very similar problem and Alexander's advice (post No.8) solved it. Had to replace the rear right window motor/regulator unit.

 

[ronspeed]

Rear Door Controller

Hey Guys,

You're the best. I've been having problems with the front windows, seats, and locks. I can easily fix the problem by pulling fuses and resetting them. Didn't make the connection between rear window and front window until I read your post.

Two questions: 1. Where can I get a rear door controller (is there another name) for my 1998 E320 and 2. The part is found in the rear door?

Thanks for your brilliance.

Ron

 

[AndyPCD]

You will probably only be able to get these from a main dealer as they have to be coded with a star machine.
You might be able to get them from a breakers or ebay or somewhere like that but will still need to be coded by a star machine

 

[ronspeed]

Thanks Willow

I do find the part inside the rear door? Any idea of cost?

Thanks again!

 

[alexander patie]

i think these rear door controllers are actually plug and play, unlike the front DCMs. cost = approx loads and loads though. first you need to find which side it is.

 

[ronspeed]

Son Helped me figure it out

My 11 year old inconveniently opened the rear side passengers side window (after I told him not to because of your earlier help). As soon as he did, front passenger window would not operate- my guess its the rear passenger side door causing the issues.

Thank you Mr Patie!

You wisdom is much appreciated......