Let me just start by saying I'm no newb when it comes to chipping ecus, I've literally chipped over 100 ecus...

I've got one now that I finished chipping and converting to VTEC (1980 board) and can't figure out why I've got a sold CEL.. Everything was done correctly with clean solder joints with great penetration. I'm trying to retune a car with this new ecu. I'm using crome with moates ostrich 2.0 and hulog. I have tuned a bunch of vehicles with this setup without any issues. When I connect the hardware to this ecu I get a solid CEL even after writing the previous tune to the ostrich, even after cycling the key. Also not able to connect live tuning in crome. Times out and says unable to connect. I have also tried to install the EPROM chip with the old tune into the ecu and cycle the key - still solid CEL. Main relay clicks and fuel pump primes but CEL is solid. No flashing via diag jumper.

When I clip j1 to return ecu to stock, the CEL goes out. I have reinspected the chipping components and don't see any visual issues..

I'm about to pull my damn hair out over this lol.. any help/suggestions would be greatly appreciated!!

 

Some pics..

 

missing resistor at R54

 

Doesn't have R54

 

It may be because it's a little blurry in the picture but a few of the solder joints for the socket look pretty bad. A better detailed picture of the board would be helpful. Maybe split each side in half (2 pictures per side).

 

Yeah I'll try and post it up. They're blurry because I had to compress them because HT wouldn't let me upload the original pics. The solder joints all look good tho...

 

Here is a close up of the backside

 

Here is a couple more shots. The light made the coating on the board look weird in a couple spots but all the solder joints look good to me...

 

I even went over all my solder joints and heated them back up to ensure they had good penetration and solid solder joints.. I can't figure out wtf is up. I'm wondering if the 74HC373 logic chip is bad or something...idk

 

His board is a "1980" no R54 on those... but yeah, thanks for the close up. I don't see anything alarming or out of place either. Latching chip is facing the right way, capacitors in right spot, no R54 to worry about, solder joints look decent... Definitely would make me lean towards a bad latching chip or the SST 27SF512 EEPROM. I assume you tried multiple SST chips though? The only thing I can't tell is the transistor in Q101 which way it's facing - IIRC it's polarized BUT not sure if that would throw solid CEL.

 

Q101 is factory, untouched. Q26 and Q37 were soldered in for VTEC conversion but I didn't think they were polarized, and they were installed oriented just like the other similar transistors - not to mention that's the VTEC portion of the board so I would think if there was an issue there it would just affect VTEC function and not cause a solid CEL.. idk tho

Yeah I tried chips as well as using the ostrich. Yeah the solder joints aren't perfect but they are clean enough that I shouldn't be having issues. I chipped the board in the garage leaning over a small table so they aren't the prettiest but solid none the less.

Have u ever seen a bad 74HC373? I'm thinking maybe that's the issue? I'll try throwing in a different ZIF socket to see if that's the issue. Never had a bad one but doesn't mean it's not possible, could definitely be the issue of there was a manufacturing defect..

 

I have only chipped a few dozen ECUs myself, but I have never heard or personally seen a bad latching chip. I have however, had a SST chip go bad before. Depending on how much heat was thrown at the chip it could have messed it up, IDK. Not trying to beat you up here, but you are positive the SST chip was the right way every time haha? Just trying to eliminate variables.

 

Lol yes, I've positive the EPROM chip was installed correctly... each and every time - not to mention, I tried with the ostrich as well to eliminate any possible EPROM chip issues. I've had EPROM chips go bad before so I always swap those first if I have an issue. I get a solid CEL regardless if it has the SST EPROM chip in it, or the Moates Ostrich.. I've never seen a 74HC373 logic chip be bad either but I'm running out of possible causes...

 

I've chipped thousands (literally) of ECUs and have seen bad 373's out of the box. They can also fail when overheated during the soldering process and...

*** It's the only thing left ***

You can cause a solid CE light with the VTEC circuitry too if you mistakenly interchange C60 with J10 - happened to me once.

BTW ALL transistors need to be installed correctly as there is an emitter a collector and a gate which need the correct voltages on the emitter and collector to "open" or "close".

 

Thanks for the facts and good insight 7rrivera7. I was hoping you would chime in here and reaffirm I was on the right track.

 

Thanks for the info, I will try desoldering the 74HC373 chip and soldering in a new one. The transistor was oriented just like the other factory installed ones in the board so i don't think that's the issue..

 

no defective Vtec components would cause a solid CEL. double-check you don't have any bridging between adjacent pins on the logic and socket. Otherwise 7rrivera7 is right, about 1% of the logics I get are defective.
hint for removing that chip, don't desolder it. clip off the legs right at the chip, pull them out one by one, then desolder the vias as needed. or, what I use is a dentist drill with a tiny drill bit to hollow out vias. These ECUs are decades old, I avoid using heat any chance I can.

 

Yeah ive had defective VTEC components and it didnt cause a solid CEL. Gotcha, yeah I agree. I use minimal heat and I desolder with a Hakko808, and a solder reamer.

No bridging at all, that was the first thing I looked for. I don't overdo solder, so I'm going to pull the logic chip and throw in a different one. Thx

 

Well, I put a new 74HC373 chip in it and still getting a solid CEL... idk wtf the deal is.. pretty irritated with it.


Guess I'm going to just have to pick up another ecu and chip it. I'm at a complete loss on this one. =/

 

Just out of curiosity, Before you chip your ECU's do you remove the manufacturers clear coating from the main board around the solder areas? Do you use a flux paste when soldering?

I always make sure to spray the areas to be soldered with carb cleaner and scrub the clear coat off. That and using flux ensures that you get 100% contact with the circuits.

Do you know anyone with a 28 pin socket/circuit tester?