''e'' Box Problems

[smart142 605]

In the past month I have had 3 smarts with electrical problems. The 3 bars of death, fuel filter light on, brake lights on etc....

Eventually the smart does not engage tranny and the owner is stranded.

The finger has been pointing to the ''E'' box located just above the battery, affixed to the firewall. Took the cover off and this is what we found. Corrosion +++ in the lower part.

Surprised the car even starts.

It's a $404 + tax part from the dealer, and it needs to be replaced. Don't know if it can be repaired??

But what causes the water to get into the E box?

I beleive its when the AC is running and a drain through the firewall gets blocked. Evilution shows how to clear....click here

Highly advisable to check this drain if you use AC.

[Utopiacdi 3]

Thanks for the heads-up, Glenn. I will check mine today.

[dmoonen 54]

Totally agree with you Glenn I had two smarts I worked on that had blocked ac drains and had Ebox issues. Cleaning the AC Drain is the first thing on my list when I start work on any smart with the front end off and it takes only a couple seconds to do.I extended mine down with a small piece to clear PVC pipe zip tied inside the original drain to prevent it from closing on my cars.I've been thinking of waterproofing my ebox's on my smarts just to give some peace in mind.One with Gunk build up, you can see why they get easily blocked

Edited August 9, 2013 by dmoonen

[smartdriver 49]

When i took apart my e-box I found a tiny bit of residue on the board where water or condensation had been but the board appeared to have been dipped in a conformal coating which would make corrosion unlikely.That is not to say that corrosion can't affect the connector but in my case corrosion on the board is unlikely.The SAM unlike the e-box has not been coated and I found significant corrosion.My car is a 2005 Cabriolet manufactured in June 2004.

Edited August 9, 2013 by smartdriver

[dieselkiki 7]

I still don't know why the E-box and the SAM box don't have a better protection against moisture and water. They just had to put all these electronic parts sealed in an epoxy compound as the engine ECU. There's no serviceable part in these electronic units anyway... It's a "use then waste" part... as alot of parts on this car unfortunately.

[scwmcan 0]

Well that depends on who is doing the servicing . I know at least one member replaced one of the relays in the SAM, and I am sure I could do so as well. To me that corrosion looks like it is repairable from the pics ( I have fixed electronic circuits that have been in worse shape before) , but I would have to look at the board it person to make sure. I do agree that these boars should be coated, but they don't need to be expoy sealed, there are conformal coatings that help protect against moisture intrusion, they are not perfect however, but will help slow corrosion damage, and let you get the boards dried out if you know you have a moisture problem with there being damage to the boards.

[MikeT 744]

When my former Peugeot 405 had a drowned Bosch MOTRONIC ECU (Peugeot had the great idea of putting it in the windshield valence area) it managed to recover from a drowning that caused a roadside breakdown with a drying out and some MolySlip Combat spray. The car ran another 200,000 km after that and I sold the ECU to someone else when we scrapped the car! So yeah, sometimes what looks like scrap may not be.

[2seatragtop 3]

As mentioned on another topic I had corrosion and cleaned the E box and then applied conformal coating. I still have some electrical problems to chase down but I don't think they are now due to the ebox. But I may be proved wrong eventually.....2seat

[WudzRydr 0]

Glenn, You're a lifesaver!

You couldn't have posted this at a better time. My wife called me last week while I was down south and told me the brake lights were stuck on in the car. I told her to just leave it and I would deal with it when I got back. After messing with the SAM and checking wiring all morning I was getting stumped. This, combined with the problems I've been having with the 3 bars and the fact the car needs both summer and winter tires replaced, almost made me throw in the towel.

Then I read this post and this is what I found:

I guess I need a new E box. I'm hoping it fixes the electrical problems I've been having.

Thanks for sharing Glenn!

[smart142 605]

the picture on the left shows an untouched e box, the one on the right has been sealed with silicone to prevent water intrusion.ps. the pine needles above the e box on the right were found in the cabin drain, they caused the water back up.

[MikeT 744]

Just a warning about silicone sealant and electronics, make sure it's not the stuff that smells like vinegar when curing, as that stuff will itself corrode circuitry over time. There are special silicones made for electronics.

[Alex 21]

Listen to Mike! He's right, get the correct stuff.

[WudzRydr 0]

I moved mine. It now resides behind the cupholder. BTW. Thanks again Glenn for the post. Found a used unit at Standard Auto Wreckers for $150+tax and it cured the problems. I think it may have actually been the source of my other electrical problems also. But only time will tell on that one.

[smart142 605]

In the past 2 days we checked 2 smarts- both had blocked outlets. One was backing up a lot of water into the car. The passenger carpet was sopping wet.E box was wet, but not corroded. Just in time.Please check that drain if you use AC

[smartdriver 49]

then I read this post and this is what I found:

In the past 2 days we checked 2 smarts- both had blocked outlets. One was backing up a lt of water into the car. The passenger carpet was sopping wet.E box was wet, but not corroded. Just in time.Please check that drain if you use AC

Curious where your e-box was located to receive damage.In my 2005 Cabrio it is mounted high up on the firewall in the passenger footwell. Edited August 21, 2013 by smartdriver

[smart142 605]

When the AC drain is blocked the water goes right onto the E box that ''is mounted high up on the firewall in the passenger footwell.''

[smartdriver 49]

[Thanks for the info.I knew that originally the e-box had been mounted in the battery box.I thought that I was safe.

Edited August 22, 2013 by smart142

[KurtMan 2]

Where is the A/C drain located?

[turbomar 13]

Where is the A/C drain located?

http://www.evilution.co.uk/index.php?id=132http://www.evilution.co.uk/index.php?id=783

[KurtMan 2]

Thanks Mario! I knew I had seen it on evolution, but sometimes I find it hard to find them again.

[Evilution 0]

Hi all.This is becoming a common fault so I'd like to put it on my site to warn others about it and include a piece about drying, cleaning and using a spray on conformal waterproof coating like we do on the Roadster SAM units to protect from water.So, if possible, I'd like permission from the people who posted photos to use 1 or 2 on my site.If anyone has a photo of the E-Box in place, that'd help and if anyone has a broken E-Box they could send me, that'd be very helpful. Cheers guys.

[smart142 605]

Hi Kane!I took those pictures, so you're more than welcome to use them. I don't have a broken E box currently, but I will send you one when I do.

[Evilution 0]

http://www.evilution.co.uk/electrical/cana...box_failure.htm

Any thoughts?

Edited July 8, 2014 by Evilution

[smart142 605]

WOW!!! You are gifted and do amazing work! Thanks from all the smart owners around the world!

[FlossyTheSmart 81]

Another worthwhile measure to prevent water from getting into the ebox is to relocate it yet again (Original location being in the battery well, second location being on the firewall). It sounds like WudzRyder above has his in the same spot mine is. In the centre pillar, behind the cupholder location. It's the same spot where Steven recommended putting the MDC Cruise Control board (on your page here). In this spot, there really shouldn't be any possibility of it getting wet.