Normal P28 problem?
 

Whats up guy's? I've been stumped by this lately because this isn't the first ecu (P28) that I've come accross like this. I've seen a few P28's with this resistor of some sort that looks to be overheated, badly burned, and cooks the circuit board. I'm curious to know if this is a common problem and if it will affect anything as far as the ecu being operational?
I've taken a few snapshots of a customer's ecu I was in the process of chipping before noticing this. It's touch to see, but you'll get the point. It's the part with my finger on it (location R135)
[img width=550 height=450]http://img38.exs.cx/img38/7844/ecu0047ay.jpg[/img]

[img width=550 height=450]http://img226.exs.cx/img226/163/ecu0031vw.jpg[/img]
[img width=550 height=450]http://img226.exs.cx/img226/5796/ecu0068dg.jpg[/img]

Re: Normal P28 problem?
 

Removed the backside cover. Here's what I found... I think this ecu's pretty much toast.

[img width=450 height=350]http://img231.exs.cx/img231/1605/ecu0015hl.jpg[/img]
[img width=450 height=350]http://img231.exs.cx/img231/9397/ecu0022bq.jpg[/img]

Re: Normal P28 problem?
 

WHOA....WTF?

I ALWAYS, test every ECU before and after chipping...that way no one can send me a bad ECU and try to blame me for it.

I did have one ECU show up with a solid CEL once, told the kid and was able to fix it after about 3 hours of troubleshooting.

But that sucker looks shot!

Re: Normal P28 problem?
 

dayum thats bad. does your camera have a macro function? :P

Re: Normal P28 problem?
 

Damn Steve thats fucked. Break out the digikey catalog and fix it. Bring it to me! I wanna try to fix it someday if you are chucking it.

Re: Normal P28 problem?
 

never seen anything like that before from years of chippin ecu's

Re: Normal P28 problem?
 

i've seen a couple with some burnt up transistors, and little burn spots on the pcb, but nothing ever that bad :-\

Re: Normal P28 problem?
 

i would put my car on it, that ecu worked when i pulled it out. when i put my new motor in i out the ecu that came with the motor in and that ecu went on the shelf. It had no check enigine light, the only thing was it acted like the iacv was bad and had a lumpy idle.I guess the turbo gods dont want me to have fuel managment, first the ---- with the vafc and now this.I should just go out and buy a FMU but i would prolly get hit by a bus on the way there

Re: Normal P28 problem?
 

just clean the pcb up and pull one from a parts ecu, i'm sure it will be fine.

Re: Normal P28 problem?
 

as long as the stuff inside the cap didnt eat away at the board or any traces, Kev is right, should be fine with a new cap and cleaned up.

Re: Normal P28 problem?
 

Wish I could get a more detailed shot. The PCB I doubt is even "cleanable", but I guess it worked fine :-\ I'll work some of my chipping magic and she'll be good as new ;)

Re: Normal P28 problem?
 

Wow, that is an interesting problem, I have ran into caps and transistors but never R135 going up. Maybe the car was wired incorrectly?

Re: Normal P28 problem?
 

Motherboards for computers had that problem with a bad batch on caps. My buddies Epox has swollen caps and 1 burst.

Re: Normal P28 problem?
 

Use Brakekleen and a tooth brush

Re: Normal P28 problem?
 

here's one that i had, no where near as bad as yours. i asked the customer if he wanted me to fix it and he said no b/c it worked fine as it was, i tested it before and after and it did work fine, but if it was mine, i would have replaced it :-\ guess where it's at :-\ if that's the same one as yours (can't really tell by your pics), then it's actually q31, r135 would be the two empty locations to the bottom right of q31, 'r' as in resistor ;)

http://www.draglab.com/hmt/projektegdizzle/burnt1.jpg
http://www.draglab.com/hmt/projektegdizzle/burnt3.jpg
http://www.draglab.com/hmt/projektegdizzle/burnt2.jpg

Re: Normal P28 problem?
 

damn. Never seen anything like that.

Re: Normal P28 problem?
 

q31's for the purge evap solenoid, someone mixed the plugs for iat sensor and purge evap solenoid at one time and fried it when the started the car. pgmfi owns you >:D

Re: Normal P28 problem?
 

Nice KEvin. Yeah it probable was Q31. I just got the only number I could read and I thought it belonged to that spot. But it looks to be in the same location. I just chipped it and sent it back to the owner because I know he needs the ecu. But I have a backup P28 here thats also got the same piece burned up (not as bad as this one pictured), and I got curious enough to ask what was going on and why they burn up.
Good info here everyone. :) Steve/Trance