MalibuJack

iTrader: (5)

Hey folks, while playing with my bench harness and different roms..

I have discovered a few things..

2003 has no vin# embedded in the rom itself
2004 I haven't checked, but its probably the same as 2003
2005 HAS the VIN#'s embedded in the ROM!

What does this mean? Well, not much, but some inspection stations with OBD-II will look for a vin# in the ECU (IF supported) to verify that the car being inspected is the same car that is connected to the computer.

I now have to see where in the rom its located, and if its something that is the same location for all years. And if its a supported feature in all years.

Mellon Racing

iTrader: (38)

now that's interesting, good find. Lucky for me they don't do emissions tests here or I could have been busted.

MalibuJack

iTrader: (5)

Damn, I think I might have a bad spare ECU..

Either that, or I inadvertantly glitched it so it won't read...

Its known to be an 05 ECU, I read it a few times.. I reflashed it with an 03 Rom, and haven't been able to read it on the bench again.

I'm not sure if the bench setup
1) damaged the ECU
2) somehow isn't working right (its been handled a bit so its possible)
3) Overwriting the 05 rom with an 03 overwrote something important, or the
roms between the 03/04 and 05 are indeed incompatible at a very low level.

Who knows, but I do need another ECU if anyone has any laying around.

I'd plug the ECU into my car and try to read it, I'll probably try to do that later.

l2r99gst

iTrader: (2)

Jack,

Do you know the address where the VIN is stored in 05 ROM?

I was reading up on Mode 9 OBD for requesting the VIN and it looks like the VIN should be stored in ASCII code in the ROM. But I searched my ROM for a few ascii coded characters from my VIN with no results.

This is some of the info I found regarding the Mode 9 OBD request:

For NON-CAN OBD the VIN is 17 characters for vehicles
that provide electronic access to the VIN. VIN characters shall
be reported as ASCII values. The response consists of the
following messages:
Message #l shall contain three filling bytes of $00, followed
by VIN character #l
Message #2 shall contain VIN characters #2 to #5 inclusive
Message #3 shall contain VIN characters #6 to #9 inclusive
Message #4 shall contain VIN characters #lO to #13 inclusive
Message #5 shall contain VIN characters #14 to #17 inclusive


Thanks,
Eric

MalibuJack

iTrader: (5)

Yeah I did the same thing, only I didn't find anything either. What I did see was flashing an 03 rom on the 05 ECU did no longer reveal the VIN# so if its hardcoded or written somewhere other than the rom, its no longer visable.