Quick overview. 91 covette with a 7749 wired in (correctly?) using the 91 memcal and the $58 mask. Diacom/pocket programmer/TunerCat
I can't communicate with the ecm with the $58 mask. If I use my stock memcal and chip, I can. I am getting a SYS that flashes 3 times and then goes back to the fuel information. 20 seconds later, SYS flashes 3 times again. Right now I am using a 27SF512 chip. I believe the $58 mask is 16k, so I offset my chip and start it at 0C000. To help troubleshoot, I burned a stock 91 program onto the same chip, used the adapter, and I could communicate with that as well. Any suggestions would be welcomed at this point.
Quick overview. 91 covette with a 7749 wired in (correctly?) using the 91 memcal and the $58 mask. Diacom/pocket programmer/TunerCat
I can't communicate with the ecm with the $58 mask. If I use my stock memcal and chip, I can. I am getting a SYS that flashes 3 times and then goes back to the fuel information. 20 seconds later, SYS flashes 3 times again. Right now I am using a 27SF512 chip. I believe the $58 mask is 16k, so I offset my chip and start it at 0C000. To help troubleshoot, I burned a stock 91 program onto the same chip, used the adapter, and I could communicate with that as well. Any suggestions would be welcomed at this point.
Do you also get a SYS flash with the stock bin in the 7749 ecm? I think in any case you will get a SYS flash because the 7749 ecm can't communicate with the CCM. You should be able to talk to the ecm with your diacom software. I am not sure if your offset is correct using a 512 chip. You could try stacking the bin onto the chip using Moates bin stacker. Seeing how you are using a 512k chip it would be 4x16k if you stack it on the chip you have now. I usually use a 27SF256 chip and place 2 16k files on it. The problem maybe with the use of the 512k chip in the ECM that was designed for either a 27C128 or a 27C256 chip. I don't have the specs for the SST 512 chips here to see if electrically they are compatible. I have used them in truck ecms and also in later F and Y car ecms that originally uses a 256k chip.
Tom, I don't get the sys light when I use the stock .bin. I also have some Atmel 29c256's that I will try instead.
Alvin, right now I am scanning with Diacom, and I put in a 91 Syclone Vin number and then select the turbo model. I have had trouble connecting to some vehicles with Diacom, but I thought the SYS light on the dash was a give away that something else was wrong.
I thought the SYS light on the dash was a give away that something else was wrong.
The SYS will flash 3 times every 15 sec while a currect-code fault is present. Have you tried grounding pin G through pin A in the ALDL connector to retrieve the CCM fault codes?
Code 41 will set if the ECM does not respond to the CCM poll. My guess is that the $58 code does not have support for the CCM, I could be wrong though...
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7749 communications trouble (need help)
