Just wanted to share my recent experience with getting my ECU wet, hopefully this will help some people in the future.

Anyway, I did some wheeling this past weekend and it was in some pretty wet stuff. Anyways, my ECU got wet. I wasn't too worried about this at first because some people say that they are pretty waterproof, THEY ARE NOT!!

My truck started acting very weird when I was wheeling and thankfully I got out before the real issues arose. As I was driving the truck, it got worse and worse. The truck began bucking, sputtering, dash lights kept flashing, and the truck kept shutting off. Not very fun when your truck is stuck in the middle of an intersection!

At this point I did not know it was the ECU causing the issues, but I had a slight suspicion. So I popped off the ECU cover and sure enough, it was wet. I didn't think it was going to be savable but I wanted to give it a shot. So I disconnected the ECU and sat it on top of my heater vent all night to make sure it dried out completely. I got lucky and this fixed the problems.

To ensure this would never happen again, I wrapped the whole ECU in duct tape, leaving no gaps for water to get in, then put the ECU and harness connectors in a plastic bag and duct taped that shut as well.






LONG STORY SHORT: Do whatever you can to seal up that ECU and keep it dry, no matter how ghetto it may be. And don't listen to people when they say these are waterproof, they aren't!! Keep it moisture free!




Alec

 

good post

 

If you completely cover every hole with tape and plastic bag... isn't there a chance of the ECU building up heat and frying itself?

 

I doubt it. Many newer ECUs are waterproof for marine applications and have no issues with this. I don't think our 22RE ECUs put out near enough heat for this to be an issue.

 

Generate enough heat to fry themselves inside a plastic bag?

1. They aren't vented to begin with. So how would sealing one in a plastic bag prevent ventilation?

2. They(ECUs/ECMs) aren't really computers, in any modern day sense of the term. They've only got about as much processing power as a pocket calculator. And how hot does one of those get while in use?

BTW, everybody with a brain in their head knows not to get there ECU/ECM wet. Anybody that says they are "waterproof" is a complete and total MORON!

 

MudHippy. You have a bad day or something? Haha sheesh.

+1 to the OP, though. Good post.

 

What he said. It boggles my mind that someone would even for a second think a wet ECU isn't going to be a problem.

Hey, go poor a bucket of water on your laptop, its waterproof dude.

 

You'd be surprised how many factory ECUs are waterproof(water-resistant), especially the ones located in the engine bay. Although I guess 80s Toyota ECUs were not!

 

Even if it says water proof I wouldn't go out and test it.

 

All I was saying is it will build up some heat, thats a given. it has holes in it and its open to the air, so it dissipates the heat pretty quick stock. Add layers of duck tape, a plastic bag, and more duck tape... and you're essentially insulating the heat inside the ECU. I was just wondering if it would produce enough heat to harm itself. My Cell phone gets pretty dang warm when you're using it alot.

I've been lucky I guess, My windshield leaks into the same area that my ECU occupies and any time I go in water, it comes in the passenger floorboards. Looks like I'll be water-proofing my ECU.

I'd like to just relocate it to the glove box, I know there is a write up on it here... just looks like too much fiddling with wires for my liking.

 

When you get stranded by a fried ECU that little bit of fiddling won't sound so bad.

 

I'd only be stranded until my friend wasn't paying attention to his '85

 

Depends on your definition of "waterproof"


Works while wet? No.

Will work again once dried? Yes.



I think the common misconception is once they get wet, they're toast, and will need to be replaced. Nope, just need to get them good and dry again, and you're good to go. I had that happen a couple times in my old Subaru while wheeling. Pull it apart, dab up the moisture with some shop towels, put it together, wheel on.

 

Thanks for the warning Carman!!!

 

Yes, although some may not get as lucky as you and I. The best thing to do is just eliminate any possibility of water penetration and never worry about it again!


Alec

 

I dipped mine in liquid rubber stuff then electrical greased the plug ins. Have had no probs with heat, and its completely sealed.

 

Wonder how the flex seal spray would work. Got to do something before i go to deep creek again.

 

Yeah, if it's only fresh water and does not short out anything (fresh water does not conduct but add minerals and/or mud and will), you could get lucky.
Agree with relocating to higher, dryer location, waterproofing but watching out for overheating... Or heck, just get this. LOL

 

I don't see how overheating could be an issue as most cars have it under the hood with temperatures way higher than the interior will ever get.

 

I had a 91 toyota pickup 4x4 with the 22rec and it was victim to a flood. it sat overnight in water up to the windows but after drying out with the doors open for a week and a fluid change it ran fine. i do not recall even touching the ECU. and if you watch top gear.... the completely drowned a toyota hilux in the ocean and it still ran afterwards.

i do understand that you said it ran but ran rough... my 91 ran witout any issues. but i would not go testing that. better safe than sorry on that one.