Whats the difference in 27 and 29c256?
 

I was messing around in TE and made a single map rom to see if I was running too rich in boost. Well, I burned it onto a 27c256 and it gave me a solid cel. So I figured it was just a bad burn. So I put the normal 29c256 back in and it runs. So I then find another 27c256 with some old code on it that was only single map and put that in. Solid cel. So I try every old 27c256 and none will work. but the 29c256 runs perfect. WTF?
I thought to the ecu that 27 and 29's were the same?

Re:Whats the difference in 27 and 29c256?
 

it depends... what kind of programmer?
the 27 series chips are UV erasable, so you would have to make sure they are fully erased.

Re:Whats the difference in 27 and 29c256?
 

29C256s are rewriteable. Just "reburn" the program over the previous one.

Re:Whats the difference in 27 and 29c256?
 

I didn't really clarify my question. What is the difference according to the ecu? I thought that they were both the same.

Cause when I put in any 27c256 I get an engine light, but the 29c256 works perfectly.

The 27's I'm using are (the one I burned today) and some old 1.29 tunes from te. They used to work.

Did I fry something in my ecu?

Re:Whats the difference in 27 and 29c256?
 

Maybe the data is corrupt from not being fully erased?