need quick help....chipping P72.....odd? *IT WORKS!!*
 

so im chipping this 95 P72 GSR ECU for this kid...its not like any of the others i have chipped... its got the outlined spot, but there is no place for me to add a resistor? the location just isnt there/marked on the baord??? you install it and you get a soild cell :-\ someone help me out here... thanks :-*

Re:need quick help....chipping P72.....odd?
 

Memeory serves me right the p72 doesnt require the 10k resistor

Re:need quick help....chipping P72.....odd?
 

1k ;) and no, p72 and p75's don't have r54, just j1, c51, and c52, they're fine without it.

Re:need quick help....chipping P72.....odd?
 

Yeah that screwed me up the first time I did a P75.

Re:need quick help....chipping P72.....odd?
 

soild CEL is fine? ::) this thing is starting to piss me off...tonight this ECU became mine, so it needs fixed...

Re:need quick help....chipping P72.....odd?
 

no, solid cel isn't fine, but it's not because there's on r54 present, i've done plenty of p72's and p75's, and none of them have r54, there's a problem somewhere else. remove the chip and cut j1, if the cel goes away, then there's a problem with the soldering, or you could have fried the 74hc. hell, i had a solid cel with an ecu and couldn't figure it out, desoldered and replaced the 74hc, still there, turns out i had missed a leg on the zif :P

Re:need quick help....chipping P72.....odd?
 

----....was hoping i wouldnt have to do that...the ECU worked before so the problem must lie in the chipping somewhere... guess i will start with the 74hc...

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

***UPDATE***

k, so i cut jumper...still soild CEL...

anyone help me out? this ---- sucks...

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

did you take the chip out also?

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

Take good close up pics of the back of the PCB, my guess is that you have somewhere joined a leg or 2 with solder.

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

cutting j1 should ecu go back to stock

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

you have to physically remove the chip also, or you get a solid cel.

Re:need quick help....chipping P72.....odd? *IT WORKS!!*
 

so tonight i got a new desoldering tool...didnt seem to work to well for desoldering my ----... so i got pissed and cranked up the heat a little on the iron and hit up every pin i soldered again and added solder where nessisary rejumped it burned another chip and....IT WORKED...

im not understanding something... you suppost to cut the jumper and everythign is supost to revert back to stock right? well i didnt touch ---- except in the dotted lines, so when i cut the jumper it should be stock agian... but it still threw a solid CEL :-\


post more about somethign that follows this...

Re:need quick help....chipping P72.....odd? *STILL NO WORKY*
 

which chip needs to be removed when cutting the jumper to check if it goes back to normal? The 74hc or the rom chip? I'm asking because my friend's ecu randomly stopped working one day. We cut the j1 and it still threw a solid cel so we just thought the ecu was fried. I'm guessing we should have taken the chip out too before desoldering everything and putting it in another ecu :P

Re:need quick help....chipping P72.....odd? *IT WORKS!!*
 

yeah, you have to remove the (e)eprom and cut j1.....

Re:need quick help....chipping P72.....odd? *IT WORKS!!*
 

damn i wish we had tried that. He tried resoldering everything and it still didn't work either so who knows...

Re:need quick help....chipping P72.....odd? *IT WORKS!!*
 

didnt work for me...