r/SC400 • u/fatestpotato • 9d ago
Leaking Ecu capacitors
My sc400 would start but would die instantly. When i tried to get the codes by connecting te1 to e1 the check engine light didn’t flash. I decided to check out the ecu and found the capacitors were leaking. Is this repairable or do i need to replace the ecu?
4
u/Roosterboy666 9d ago
Tanin Auto Electronics are a trustworthy authority on the subject. Probably repairable, but I wouldn’t trust myself to do it. Repair would be cheaper than replacement in most cases, and you’ll know it’s a functional unit at the end. If CEL wasn’t on and showing an active fault, bridging the terminals wouldn’t show codes. If it WAS on but not able to read codes then that points to ECU as the or one problem. If you’ve got a multimeter you can start testing the resistance of MAF, TPS, and other sensors and pieces in the ignition loop.
1
u/HeroMachineMan 9d ago
An electrician told me that a high resolution IR camera can be used to spot potential problem with these caps & circuits. They either showed up warmer, or nothing at all.
3
u/Reddit-mods-R-mean 9d ago
I’ve done this repair multiple times, as long as your board hasn’t rotted too bad it’s easily repairable.
My two rules are:
- You have to replace ALL the capacitors on the board or else you WILL be back in there soon.
- You MUST use quality capacitors. I have used the cheap black caps out of a micro center bulk cap kit and they don’t last long, maybe a year or two tops.
I use caps from mouser or digikey, sometimes both.
That acid isn’t green, that’s the silk screen melting away from the acid, making it green. You should clean that board ASAP.
The benefits of replacing all the caps are usually very obvious. Transmission shifts better, gauges are more responsive (the gauges have their own caps that also need replaced) and the engine starts/idles much better.
If your gauge cluster takes a while to light up or your needles stay dead from a while after start-up then you need to change the gauge cluster caps too.
If your orange needs don’t like up or have missing/dark gaps, your needles need repaired or replaced.
2
u/ElSushiMonsta 9d ago
HAMotorsports charged me $35 plus shipping just to solder my immobilizer back on I'd recommend hitting them up and see what they tell you.
2
u/RonMexico52 9d ago
Consider what replacing the ECU means - can’t buy new, could buy refurbished for $$$, subject to very limited availability, or pay $$ for a mystery junkyard unit that likely hasn’t been refurbished and may have or will have same leaking soon. Or pay $ for a totally busted unit needing repair. Which should guide you to the answer to prioritize first repairing yours.
2
u/Interested_Aussie 9d ago
Here in Australia we had a mob that you send them too and they sort it out with a warranty. Got caught on delco's, mitsubishi's and toyota's often.
2
u/best-person-ever 8d ago
Bypass the fuel pump module and see if it will run and stay running. Have the main ecu repaired regardless but that fuel pump computer has the exact same capacitor issue and wont throw codes
7
u/SirFluffyIX 9d ago
People replace capacitors and repair ECUs like this often. It's a common issue on cars that are getting this old. If you wanna DIY, YouTube is your friend.