Merc 2012 e220 Cabriolet - electrical failure when rain/damp
Discussion
Good day
I have a Jan 2012 e220 cabriolet that has a very strange problem, that I think I have identified the broad cause, but not the issue.
When it rains and now with the weather change, damp (lots of condensation in the morning), my car will start perfectly, run and sound great (the fan kicks in so the temp is managed), but...all the warning lights are on, the sensors are tripping out e.g. run flats, bonnet, headlights, parking - all those little gadgets are coming up as inoperable.
Radio won't some on, no windscreen wipers, no indicators (although hazards come on) and I can't get it in to gear (auto).
The only thing I can get to work are the windows, hazards as mentioned, I can lock the car and open the boot, but only with the key, the internal switch and rear manual handle do not work.
I learned that possibly the drains were blocked and getting the fuses wet etc, cleared the front ones and all the fuses boxes seem dry. I did have, up until recently a sloshing noise behind the driver seat (to the right) and undid the drain plugs underneath the car and water (a lot) drained away.
The only way I can get things going again is run it in the hope the engine warmth dry whatever it is out. This can sometimes takes one minute, but yesterday and today 45 mins. I will put it into the garage, but I think it would be wise to see if anyone has experienced the same things, before I hand my mortgage over to Merc. This is my first Mercedes, which is a shame for them.
Here is what I have concluded - it's moisture related, the colder weather is making it worse, the water ingress could be the problem which i may have sorted, but the increased moisture in the air is either adding to it what was there or the main cause of the problem (the sloshing doesn't happen any more)..
I have a video of what happens in the cabin - I'll try to post it
https://youtu.be/FTwNLf_8G-c
Here is a pic
I have a Jan 2012 e220 cabriolet that has a very strange problem, that I think I have identified the broad cause, but not the issue.
When it rains and now with the weather change, damp (lots of condensation in the morning), my car will start perfectly, run and sound great (the fan kicks in so the temp is managed), but...all the warning lights are on, the sensors are tripping out e.g. run flats, bonnet, headlights, parking - all those little gadgets are coming up as inoperable.
Radio won't some on, no windscreen wipers, no indicators (although hazards come on) and I can't get it in to gear (auto).
The only thing I can get to work are the windows, hazards as mentioned, I can lock the car and open the boot, but only with the key, the internal switch and rear manual handle do not work.
I learned that possibly the drains were blocked and getting the fuses wet etc, cleared the front ones and all the fuses boxes seem dry. I did have, up until recently a sloshing noise behind the driver seat (to the right) and undid the drain plugs underneath the car and water (a lot) drained away.
The only way I can get things going again is run it in the hope the engine warmth dry whatever it is out. This can sometimes takes one minute, but yesterday and today 45 mins. I will put it into the garage, but I think it would be wise to see if anyone has experienced the same things, before I hand my mortgage over to Merc. This is my first Mercedes, which is a shame for them.
Here is what I have concluded - it's moisture related, the colder weather is making it worse, the water ingress could be the problem which i may have sorted, but the increased moisture in the air is either adding to it what was there or the main cause of the problem (the sloshing doesn't happen any more)..
I have a video of what happens in the cabin - I'll try to post it
https://youtu.be/FTwNLf_8G-c
Here is a pic
Edited by solosmate on Tuesday 3rd October 11:10
First of all do not worry as you have not broke anything!
All batteries ware out over time and the type of usage can cause this to happen quicker than others.
All the warning lights have been tripped due to low voltage.
New battery, clear any faults and away you go.
This is common with vehicles using a lot of electronic sensors and the like.
Most people jump in, lights on, radio on, heated seats on, defrost screen on, and the battery gets hammered.
This time of year or a hard cold snap will test everyone's batteries.
I use a slow charger to keep the battery in top condition.
I put it on once every two weeks and it tells me the voltage.
This is useful if you either do short journeys where you never get the full charge into the battery or if the vehicle is only used every few weeks.
All batteries ware out over time and the type of usage can cause this to happen quicker than others.
All the warning lights have been tripped due to low voltage.
New battery, clear any faults and away you go.
This is common with vehicles using a lot of electronic sensors and the like.
Most people jump in, lights on, radio on, heated seats on, defrost screen on, and the battery gets hammered.
This time of year or a hard cold snap will test everyone's batteries.
I use a slow charger to keep the battery in top condition.
I put it on once every two weeks and it tells me the voltage.
This is useful if you either do short journeys where you never get the full charge into the battery or if the vehicle is only used every few weeks.
If it were my vehicle I would change both batteries.
If they are both the origonal ones then both will have seen some action.
It also means that you are starting on an even footing with no battery woes to contend with.
Mind if I had to pick one option then the aux would be the first choice but would have me wondering when the main would let me down?
If they are both the origonal ones then both will have seen some action.
It also means that you are starting on an even footing with no battery woes to contend with.
Mind if I had to pick one option then the aux would be the first choice but would have me wondering when the main would let me down?
The latest update to this thread.
So, the car is experiencing a CAN Communication error, which is not allowing some of the systems to start up. I have found a way to get it started by just turning the key - on and off before turning over the engine - do this a few times and it starts.
Garage want to replace the front fusebox, but don't know if that will work, but all the systems are connected to that - so not a bad suggestion. I am not sure if the logic feels right on that though - why would my new work around suddenly result in the existing potentially faulty fusebox working.
An electrical conundrum. When it's up and running, you'd never know there was an issue - so the controller units and CPU's must be fine too. They've clearly hit the nail on the head with the CAN issue, but how do you isolate the problem?
Batteries have been tested and are fine.
So, the car is experiencing a CAN Communication error, which is not allowing some of the systems to start up. I have found a way to get it started by just turning the key - on and off before turning over the engine - do this a few times and it starts.
Garage want to replace the front fusebox, but don't know if that will work, but all the systems are connected to that - so not a bad suggestion. I am not sure if the logic feels right on that though - why would my new work around suddenly result in the existing potentially faulty fusebox working.
An electrical conundrum. When it's up and running, you'd never know there was an issue - so the controller units and CPU's must be fine too. They've clearly hit the nail on the head with the CAN issue, but how do you isolate the problem?
Batteries have been tested and are fine.
Did you just test the batteries or change them?
Reason I ask is I had mine tested on the latest test machine over night and all came back good.
Guess what? The battery was knackered!
Changed the battery and all sorted.
Mind if your voltage has been low at some point then this can cause your type of problem.
The modules can forget their instructions and need resetting using a special tool.
If it is a water ingress problem then God knows where to start as not only do you need to find and fix the problem but also find and fix where the water is entering the vehicle.
Try getting hold of a battery charger to see what the voltage is each morning before you start the vehicle.
Reason I ask is I had mine tested on the latest test machine over night and all came back good.
Guess what? The battery was knackered!
Changed the battery and all sorted.
Mind if your voltage has been low at some point then this can cause your type of problem.
The modules can forget their instructions and need resetting using a special tool.
If it is a water ingress problem then God knows where to start as not only do you need to find and fix the problem but also find and fix where the water is entering the vehicle.
Try getting hold of a battery charger to see what the voltage is each morning before you start the vehicle.
Edited by Dark Star on Friday 13th October 15:27
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