Cascade Crew

91camaro_rs · Posted: Sun Jan 16, 2011 1:41 pm Post subject: code 51, prom error

i have been trying to figure out why my speedo wont work and i checked the codes and only had one which was code 51 which is PROM error, could this be because im using a 305 prom, even tho the chip is a 350 chip?

anyone have a 350 tpi prom laying around?

aaron_sK · Posted: Sun Jan 16, 2011 5:16 pm Post subject:

Wrong checksum in the burned chip throwing a prom code, maybe?

91camaro_rs · Posted: Sun Jan 16, 2011 5:44 pm Post subject:

what is the checksum? it says its at 5154...whatever that means

idk if the code and speedo are related or not, i just want my speedo and odo to work!

aaron_sK · Posted: Sun Jan 16, 2011 5:53 pm Post subject:

Not sure if this is your problem specifically, but on a 6E you set the Mask ID to 'AA' to disable the checksum. Without that it will throw a code.

MrMike98 · Member Joined: 18 May 2010 Posts: 231 Location: Bremerton

lets see if i can get this..
the big long blue thing inside computer is the MemCal.
inside memcal is the PROM chip a black thing with 28 pins.(this is the place the program is stored)
now the memcal is specific to 305 or 350..
the PROM is the same in both except the programming is different.
the above for $8D and 740tpi computer.

i hope that make sense....
Mike

MrMike98 · Member Joined: 18 May 2010 Posts: 231 Location: Bremerton

Code 51 is for bad/incorrect Memcal-check to be sure its seated and is correct for the motor i.e. 305-350.
so i think this is your issue, if your using a 305 memcal...

Twilightoptics · Posted: Sun Jan 16, 2011 6:48 pm Post subject:

The ECM is the same for 305s and 350s. It's the injection system that changes the computer and subseqauently the memcal.

The Memcal is the 2 chip piece that plugs into the ECM with the blue cover.

The EPROM is the larger brown chip. It holds all the data for the ECM to make it's calculations off of. So for a 350 it's specified to 22lb/hr injectors ETC. The EPROM is physically the same for a 305, it's just programmed for the 305 parameters.

The 2nd chip in the MEMCAL is the "limp home mode" default parameters. If you have code 51, you burned the EEPROM wrong or have the chip inserted backwards, and the ECM is running off the limp home mode chip. Limp home mode chips are different for 305 and 350. So if you have a 305 memcal, all you're using is the 305 limp home mode.

91camaro_rs · Posted: Sun Jan 16, 2011 7:34 pm Post subject:

Ok so I do have a 91 tpi 305 memcal, with a 350 eeprom chip burned, ill try turning the chip around, but if it was backwards wouldn't it run real bad, everything works great except for my speedometer and that's what I want to fix

Twilightoptics · Posted: Sun Jan 16, 2011 8:19 pm Post subject:

If you have code 51, the engine is running on the stock 305 config from limp home mode. Not the chip you burned.

aaron_sK · Posted: Sun Jan 16, 2011 8:22 pm Post subject:

Also note that when you put the chip in backwards, it wipes itself, so don't go flipping it around and expect it to work. Gotta reburn first.

Twilightoptics · Posted: Sun Jan 16, 2011 8:24 pm Post subject:

Never had that problem with John's car or Mine.

aaron_sK · Posted: Sun Jan 16, 2011 8:31 pm Post subject:

Ran into that issue with the IROC. Don't know if it was something with the Moates setup or what. Shrug

91camaro_rs · Posted: Sun Jan 16, 2011 8:55 pm Post subject:

So how should the prom be orientated with the chip and the adapter, anyone have pictures?

MrMike98 · Member Joined: 18 May 2010 Posts: 231 Location: Bremerton

with memcal in hand pins down the limp home chip on your left , the eprom on the right. the eprom mark(half moon) is on the right side of chip.
i.e the chip faces out,so the half moon mark is on the right side of memcal not in the middle(left side of chip. chip can only go one of two ways. mark on chip to left or right. it faces right.
i hope u understand.

Dewey316 · Posted: Sun Jan 16, 2011 9:53 pm Post subject:

I've never actually gotten a code 51, when I have put chips in backwards, or not seated, my SES light flashes really fast, it doesn't just throw a code.

When you saved the bin in turner-pro did it calculate the checksum? Also, what chip are you using, and what offset did you use, or did you stack the bins?

91camaro_rs · Posted: Mon Jan 17, 2011 12:45 am Post subject:

the prom im using is a AXXB or AXXF i dont remember but its a 91 tpi 305, and the bin im using is AUJP. and i saved the bin into a file once i downloaded it and opened it in tunerpro and burned it to a chip and put it in the car, and i have no idea if it calculated checksum, and im pretty sure i didnt stack the bins, and idk how to change the offset, idk what the offset even means haha

im a complete NEWB to this chip burning business

Dewey316 · Posted: Mon Jan 17, 2011 1:27 am Post subject:

That is probably the issue. The stock bin is 32k. If you are using a 27SF512 chip, it is a 64k chip. So you either need to stack 2 bins to make a 64k bin, or you need to burn the chip with the chip start and end set to 008000 and 00FFFF respectively. And the buffer start and end at 000000 and 007FFF.

--John

91camaro_rs · Posted: Mon Jan 17, 2011 10:44 am Post subject:

where do i go to set those numbers?

Twilightoptics · Posted: Mon Jan 17, 2011 10:50 am Post subject:

I've NEVER had to edit the start/end parameters.

Just find the size of the chip, and burn copies on it till the chip is full.

AKA staking the bin.

Tuner pro has this function.

91camaro_rs · Posted: Mon Jan 17, 2011 11:02 am Post subject:

ok i stacked the bins in tuner pro, im puttin the chip in the car as i speak ill let ya guys know what happens

ok so speedo doesnt work, it still has a code, but i got it to data log but it wont record the session cause it said error creating log file