ECU ROM differences for 4eat and 5mt?

[engr]

Are there any ROM differences between the 2? I have a AF423 ECU, and if I use images that came from 5mt, will it work?

[qoncept]

I havent compared them, but I imagine it'd work just fine. Cobb doesn't have different maps for AT and MT cars. In the 2004-2005 images I've looked at, all the tables are the same.

[crazymikie]

I know you can use an AT ecu in a MT car, but I'm not sure if the reverse is true- there are certainly a few subtle differences in the tuning- I know for a fact the CL/OL logic is different.

Mike

[engr]

Are there any specific functions that exist for the 4eat ecu that accomdates the shifting? or is that all done in the TCU?

can someone do a comparison between the same ecu in both MT and AT? I don't have any ROM collection to do this with..

I just ordered my Tatrix cable, and it woun't come for at least a week.. So I can't upload the dump yet... I tried to do a dump with the AP cable, and it didn't work..

Thanks guys..

[qoncept]

What MY is your car? I know there is an AT map in the 2004/2005 tech forum, along with a bunch of MT maps. I don't have the time to do it right now, but you could do a diff between them and use the data offset thread in the same forum for reference. I use a program called Hexprobe which seems to be pretty helpful but I'm sure there's got to be something better out there.

[cboles]

Fairdell HexCmp is pretty decent at hex diffs. I would like to add a feature to diff maps in EcuFlash. The nice thing about that is you can compare ROMs where the maps aren't even in the same location.

[engr]

Mines is a 2002 USDM wrx 4eat wagon.

I did a "comp" with a 2002 5mt and 2002 4eat.. but I don't think they're from the same ecu... here are the results..

Compare error at OFFSET 204
file1 = 39
file2 = 43
Compare error at OFFSET 21C
file1 = 30
file2 = 31
Compare error at OFFSET 21D
file1 = 0
file2 = 1
Compare error at OFFSET 21E
file1 = 11
file2 = 5
Compare error at OFFSET 21F
file1 = 22
file2 = 29
Compare error at OFFSET 313
file1 = 9A
file2 = C2
Compare error at OFFSET 317
file1 = E4
file2 = F6
Compare error at OFFSET 31B
file1 = 6
file2 = 18
Compare error at OFFSET 31F
file1 = 8
file2 = 30
Compare error at OFFSET 322
file1 = 62
file2 = 63
10 mismatches - ending compare

I don't know what those correspond to...

[crazymikie]

Like Colby said, you can't just do a straight hex compare since the maps aren't in the same location (or are even the same size) between the AT and MT ECUs.

I think all of the shifting information is in the TCU, however, doesn't the AT hold boost between shifts whereas on an MT, your boost would fall off? Does that mean there may be fueling differences between the two ECUs? IIRC, the UTEC required different fueling schemes for MT/AT.

Just thinking out loud......

Mike

[qoncept]

Mike, his diff shows only a few changes though, and only a few are consecutive. Those images were almost identical except for a byte here and there, and they're all at the beginning of the file. None of the values I've looked at are before 0x20000.

[crazymikie]

I thought the diff from engr stopped at 10 differences, but there were still more. Maybe I just misunderstood the output.

I know there are at least two differences in the CL/OL logic around 0x28000 (I haven't looked at it in a while- I could be wrong in that address, but I know there are differences- that's how I figured out some of the values in that area )


Mike

[engr]

I guess I answered my own Question here.. I did a dump of my friends stage 2 cobb and compared it to my stage 2 cobb, same year and it's identical.. so there are no difference (at least in the cobb maps)..

[crazymikie]

Cobb uses the same map for all cars- MT or AT. There is no Accessport for a 4EAT vs a 5MT.

I know in the 2002 ROM, there are different boost/wastegate maps for the two different transmission types. Remember- the AT holds boost between shifts whereas the MT doesn't (well, I can't shift fast enough at least).