Hello Gents.

My 98 C43 isn't registered at the moment, so it's been sitting. I haven't touched it in the last 2 weeks, just every week or so I go out and start it to let it idle for a few minutes.

Well, I go out the other day after an excessively rainy week to find that my keyless isn't working. I use the manual key and it triggers the alarm. I assume the battery got low. As a test, I try to crank it and the car starts right up. Strange...

Then I notice the rear right floor is soaking wet! Now that the car is running, everything is working fine. I hook up my wet vac and let it run sucking up water from the rear floor for a good 2 hours. It's a small wet vac, but it fills is up. I empty it and keep going and after another 2 hours it's barely got any water in it so i guess that's as far as I can go with a wet vac.

I lock it back up and come back a few days later this weekend to figure out why it's all wet and give everything a good checkup.

Except now the car won't unlock keyless again, so I use manual again. Alarm doesn't trigger. I start the car no problem again, and roll down the windows. Put the car in the sun with the windows down to help dry it out. I check the wet spot and it's still very wet. I hook up dry vac again and let it go a couple hours. It's night time, except now my rear left window will NOT roll back up. I think i have a blown fuse and and go to check in the trunk. Trunk will not open. Keyless won't open it, interior won't open it, and rear button won't open it (it worked fine before). Key won't go in the lock to try and manually unlock it presumably due to rust. So luckily I had the rear sets loose and I fold them down to enter the trunk. All fuses are good back there and trunk is bone dry.

So, keyless inoperable, rear window won't roll back up, and trunk won't open. I checked every fuse on the car (front and back) and nothing is bad. Any ideas?

 

Sounds like very bad vibes...

Ok regarding the wetness inside, do you have a sun roof? If so, it could be a rear drain pipe which is blocked, perished or disconnected, providing there is a drain pipe(s) in the rear corners.

Regarding the electrical problems, sorry I don't have any ideas.

 

Hey man,

Along with what DRB said, remove your cabin air intake in front of your windscreen, in the centre is a drain with a flap at the end down low behind the firewall, use a suitable tool to clean this out. you can try from behind the engine but this is not very effective, this area gets REALLY blocked and will flood into the cabin so check under front carpets also.

Your electrical problems point towards DCM 3 and 4, the modules in your rear doors,this is extremely common fault but not obvious. these will cause the front windows to stop intermittently,along with boot lock and the key access,sometimes the key will start failing from distance,or door IRs will stop,this is because they drag down the interior CAN system and everything else on it. with SDS you will most likely notice a CAN high fault,SDS will not show DCM3/4 are faulty, you will still be able to communicate with them in most cases.

To test, simply unplug the rear door modules one at a time, you will see everything start to work again.

Disconnecting the battery sometimes fixes this for a short period.

the modules are expensive

 

Are these modules inside the doors?

 

Yes they are in the rear doors

https://mbworld.org/forums/c36-amg-c...rf-pickup.html

 

thanks, Pagz!

haven't had time (plus I'm sick) to deal with it just yet. I've got something covering the open window for now

but the ABS ESP lights are staying on and my blower motor won't spin now. hooray.

I read that thread and can also note that this car's range on the keyless has always been REALLY short, like 10 feet from the car. maybe I had a problem since I bought it and it's only now beginning to show itself. the window that won't roll up is on the opposite side of where the leak apparently is, afterall.

 

Hope your good K.,

Did you try to diagnose the car..?, what is the battery voltage..??, do you know if SAM module been replaced..???

ZAYED,,

 

I do not have anything other than OBD2 scanning at home, which is not helpful. I have a friend with STAR scanner but his shop is 40 miles away and the car is not registered or insured at the moment. Once I replace a blown ignition coil and leaking heater hose I can transfer the registration/insurance and drive it to his shop for a test.

The battery is out of a 2014 BMW 135i and is only rated at 750 amps, I think. It starts the car without issue, which leads me to believe the voltage is fine.

 

Using STAR will help a lot to see what's the fault stored to the ECU, and prevent spending time & $$$..!,,

is your can has this comfort module..?, if so, it could be something wrong with it..!!



ZAYED,,

 

yes, all US w202's have this module.

I had MAJOR problems with this module in my 1994 C280 when the trunk flooded with water! But I don't think i have issues with it now. With my old car, even with this unit disconnected I could still operate locks, blower, etc. As far as I can tell the comfort module only controls window motors, sunroof, and the auto-up/down feature when you press the 2nd "click" on each button.

the fact that I now have issues with multiple other systems not related to the comfort module leads me to believe my comfort module is fine. I also had very short range on my keyless prior to this week, and now my keyless isn't working at all. I suspect it's a DCM failure.

It's a black car with black leather and my AC is broken, so I'm not happy to drive it in these hot months!

 

Did you check if any water sneaks to the vacuum pump, try to disconnect it then return it & see if any difference,

or maybe water reaches to the OCP circuit board, caused some interrupt signals..!

ZAYED,,

 

where is the OCP circuit board?

 

This OCP circuit board got Hz frequency receiver, it's in interior roof light, see post #9 in Pagz thread above.

ZAYED,,

 

disconnected and reconnected battery, was able to roll that window back up and pop the trunk!

got a busted heater hose that's impossible to find, so can't fix the leak and run it very long right now

 

Sulaco, Zayed hello

I'm not familiar with the comfort module, however all your symptoms point towards rear door modules DCM3 and 4, as Zayed suggested best to use SDS,Look in EIS module faults, if it shows CAN high fault try unplug DCM3/4 it will will change state immediately, if not try unplug other modules on the interior CAN ie DCM1 and 2(front doors), OCP(overhead lighting module on headliner),LCP(lower control panel - incorporated in window switches), and even your comfort module if need be.

If no SDS, next time it fails do not reset the battery,instead remove rear door cards and unplug DCM3/4 individually.

 

Hi Paul,

As usual, your good wisdom advice..

ZAYED,,

 

Figured it out. The leak was a clogged drain in above the blower motor. Sitting still in the rain for a few weeks made it overflow and into the blower motor, down into the car. It's been doing this for some time.

I removed the seats and all the carpets and the passenger side has been getting wet for years. Must be why my SRS light has always been on because that sensor looks completely ruined. It's a cheap sensor though.

Anyway, fixed the leak. Letting everything dry out before I start trying to figure out what all has failed from the moisture. I only pray it's not a CAN module...