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As per this thread, I idiotically managed to get my car's ECU wet.
An auto electrician tried to do a diagnostic, but after several "failed to communicate with ECU" messages, pronounced it dead. Or at least in serious need of a miracle.
He checked it on Saturday morning and after that we put it in a bowl of rice in the hope that it would draw out the moisture that might be the cause of a temporary issue. But I took it out just now (Monday morning) and it has made no difference.
PUHLEEEEEZE tell me there is a solution to this that does not need bucket-loads of money?
Worst case, send it to an ECU repair service. Even if yours cannot be saved the service can still pull the data out of the PROM and program the data into a replacement unit.
The being wet is likely not going to be the issue. The issue will more likely be ESD. ESD is Electro Static Discharge, and just touching the board that you have out or placing it on the wrong thing can pretty much destroy the micro electronic devices on the board. Just do a study about it. In simple terms you never touch one of those boards unless you wear a properly grounded wrist strap, or make real sure you are discharged.
Wet? Go on you tube and you can see people washing them with alcohol and even soap and water or water in an ultrasonic cleaner. So wet is not an issue with no power applied to the board.
And rice? A low temp oven is better.
I have to say the video of someone willfully placing an IC board into a pre-heated 385 degree oven as a means of repair was hysterical. Thank you. Obviously the guy in the video is unfamiliar with the term "thermal shock" and how sensitive to damage today's modern integrated circuits are to temperatures above even 130 degrees for a few short minutes. At the very least, that oven stunt is shortening the lifespan of all the IC's on that circuit board by thousands of hours at least. As someone who spent more than a few years designing and testing various computer systems to determine MTTF (mean time to failure) under various extremes of operation, that oven video was a classic example of how NOT to treat modern electronics. I just love some of these so-called home remedy YouTube videos. Great way to needlessly destroy expensive electronics, that could have been properly repaired.
As to OP's problem, if the ECU was wet, but no power was connected to the ECU at the time (meaning NO DC inputs connected to the device), the rice trick might have worked if the device was handled properly. However, he doesn't state how the ECU became wet in the first place, so we're missing some key info. If the ECU was opened up or in any way mishandled without proper grounding to eliminate the potential for electro-static discharge, then the ECU could have also been damaged in that manner. Again, key info missing. In any event, based on OP's post, I would have to agree with the mechanic's assessment. The ECU is bricked. One or more of the IC's on the circuit board are inoperative.
If he wants to try and salvage the ECU, there are some ECU repair places out there, as has already been suggested, that be able to repair the unit. Worse case they end up having to clone him a new ECU.
Thank you for everyone's replies, I appreciate the effort
Originally Posted by PaulE550
As to OP's problem, if the ECU was wet, but no power was connected to the ECU at the time (meaning NO DC inputs connected to the device), the rice trick might have worked if the device was handled properly. However, he doesn't state how the ECU became wet in the first place, so we're missing some key info. If the ECU was opened up or in any way mishandled without proper grounding to eliminate the potential for electro-static discharge, then the ECU could have also been damaged in that manner. Again, key info missing. In any event, based on OP's post, I would have to agree with the mechanic's assessment. The ECU is bricked. One or more of the IC's on the circuit board are inoperative.
If he wants to try and salvage the ECU, there are some ECU repair places out there, as has already been suggested, that be able to repair the unit. Worse case they end up having to clone him a new ECU.
My apologies... The short answer is that the ECU got wet because I am an idiot.
The detailed explanation: I cleaned the engine with a water-based engine cleaner. Just the engine and surrounds, I did not open the dust cover to where the fusebox sits. I rinsed it off after 5 minutes (as prescribed on the engine cleaner bottle). I used a hosepipe, water turned on low, didn't squirt, just rinsed off gently. There I wasn't being an idiot yet.
Then I saw there was a lot of dust and sea sand in nooks and crannies (car comes from the coast) and I tried to rinse that off too. Still no high-pressure hose, just the garden hose. But then I saw that the fusebox is closed with only one retaining clip, not two, and it is gaping open. Panic stations! Jerked the hosepipe away, closed the tap, opened the fusebox and saw water drops everywhere.
Used a vacuum cleaner's blow function to try and dry it, but when I switched on the ignition, there were error lights everywhere and the starter won't even turn. I thought (being such a genius) that leaving it overnight might rectify it. It didn't.
I got an auto-electrician to come and check and he diagnosed serious problems, advised that I try and dry it out in rice. After 36 hours, no change.
I delivered the ECU to him and he identified various damaged resistors/diodes/transistors/whatevers as well as damage to one of the processors. So, no fix.
"Used a vacuum cleaner's blow function to try and dry it, but when I switched on the ignition, there were error lights everywhere and the starter won't even turn." Just as an FYI for the future, that's the moment you shorted out all the components you mentioned on your ECU, as water obviously had seeped into the unit somehow. There are safer ways to clean around the electrical systems in your engine bay that don't entail the use of water. Just chalk it up as a learning experience and don't beat yourself up about it. Hope your back on the road soon.
I have to say the video of someone willfully placing an IC board into a pre-heated 385 degree oven as a means of repair was hysterical. Thank you. Obviously the guy in the video is unfamiliar with the term "thermal shock" and how sensitive to damage today's modern integrated circuits are to temperatures above even 130 degrees for a few short minutes. At the very least, that oven stunt is shortening the lifespan of all the IC's on that circuit board by thousands of hours at least. As someone who spent more than a few years designing and testing various computer systems to determine MTTF (mean time to failure) under various extremes of operation, that oven video was a classic example of how NOT to treat modern electronics. I just love some of these so-called home remedy YouTube videos. Great way to needlessly destroy expensive electronics, that could have been properly repaired.
Do the search, it is common practice to do the reflow thing on a circuit board. Battery should have been disconnected as well.
And some places solder their boards like that.
"Used a vacuum cleaner's blow function to try and dry it, but when I switched on the ignition, there were error lights everywhere and the starter won't even turn." Just as an FYI for the future, that's the moment you shorted out all the components you mentioned on your ECU, as water obviously had seeped into the unit somehow. There are safer ways to clean around the electrical systems in your engine bay that don't entail the use of water. Just chalk it up as a learning experience and don't beat yourself up about it. Hope your back on the road soon.
Thanks for your kind words...
I understand exactly where my actions turned idiotic and it has been an expensive (and unnecessary) lesson. I will try and stop feeling sorry for myself now
The good news is that I will probably find a used ECU for between ZAR1 850 and ZAR2 500 (US$121 - US$229).
Waiting for a workshop and two breaker yards to get back to me. But that will have to wait, as I'm flying to Iceland tonight for 11 days and then Kenia for two weeks - guiding motorbike tours.
The car with the toasted ECU waited patiently for just more than a month for me to get back from touring Iceland and East Africa. After sleeping off the flying and beer fumes, I went a large breaker yard not far from here. They only do Mercedes-Benz. I managed to get an ECU from a C240 for R1 500 (US$100) and they referred me to a former Mercedes sparkie who swappeded one chip from the toasted ECU to the new one. Cost also R1 500 (US$100).
Went home, plugged it in, turned the key and the car started immediately. I can't remember a sweeter sound...
That fix lasted for just over three years, and the ECU was declared "unfixable" and the car has been standing since November.
This time I bought a whole "lockset" -- ECU, instrument cluster, ignition barrel, and driver's door lock and key. All of this VIN-connected. It was a battle to source, but finally manged to get it at R5 000 (US$260 / GBP210).
But the connectors do not match. So I shipped it back to the breaker's yard, and got a refund after some time. And bought another set from another breaker. Same story. Returned, waited for refund.
Then bought a set of a mechanic who had bought a C240 sedan with a mechanical issue that he could fix, but then found the licence is so far in arrears that it would be stupid to pay that up to date, and decided to strip and sell the car for parts.
But again, the plugs do not match.
Please, someone, tell me their is a workaround where an adaptor-type connector "loom" can be made up to fix this? Please?
And now theses ECUs have become like hen's teeth. Is there any advce of where I can buy in the UK? I have friends in the UK coming to visit in a month or so, so I could have delivered to them.
08-19-2019, 04:52 AM
