ecm checksum eror

midwest272 · Post by **midwest272** » Sun Oct 12, 2008 6:26 pm

I am using tunerpro for mefi tuning on a mefi-1 boat app. I have been able to change values in BPW to MAP tables to affect A/F ratio changes succesfully. When I went to modify the base spark tables the first upload went thru then the ecm became unresponsive and throws a code 51 (checksum error) is there anyway to clear this from the ecm or am I toast.
I thought the software was supposed to tell you of a checksum error before uploading but no notice was given.
Not able to download from ecm and has shut down all alarms and fuel pump startup. Says not connected to ecm. Man and I was getting close.

Six_Shooter · Post by **Six_Shooter** » Sun Oct 12, 2008 9:06 pm

Have you "disabled checksum by uploading"?

Tools>Preferences>ALDL/Emulation tab. Check the "Disable Checksum by Uploading" option. Make sure you have the correct bit selected. I'm not sure what it is ofr the MEFI ECMs, 7747 uses "0x04" , while 7730 and similar uses "0x08".