P04 Flashing Troubles
Posted: Wed Apr 30, 2025 10:28 am
I would like to preface this by saying I am very new to PCM programming and it is most certainly my mistake whatever happened.
I used an obdlink LX to read a bin file of my 2001 Buick century custom with a 3.1L engine. It appears this was the easy part. After looking around for an xdf and not finding much, I downloaded Universal Patcher, which found a "mostly compatible" (OS 12207879) table for the bin I was able to dump (OS 12214427). After making the desired modifications, which consisted of removing some DTCs related to EVAP and EGR. As well as playing around setting the speed limit to 85-90mph and AFR to 14.8.
Saving with Universal Patcher updated the checksum value at address 000714F0. However, upon flashing this to my ECU I encountered some problems. All appeared to be going well, but I saw two checksums on the ECU were now values that were not the same as the file. I was able to dump my ECU on the bench after inputting the OS version as it appears to be badly corrupted or deleted. Attempting to flash the *original bin doesn't result in any change.
*Now looking closer at everything that I have, photos, logs, etc. It would appear that I must have edited my bin file and it is no longer the exact same as from the factory ECU bin. I just noticed that the 006000-007FFF range checksum is different than the first log I have. Unless the ECU program is the one that changed if it was like a parameter or DTC that was cleared. I already ordered a replacement ECU, but some help regarding this would be appreciated as I would very much like to learn what I can about ECU programming. Thanks!
I used an obdlink LX to read a bin file of my 2001 Buick century custom with a 3.1L engine. It appears this was the easy part. After looking around for an xdf and not finding much, I downloaded Universal Patcher, which found a "mostly compatible" (OS 12207879) table for the bin I was able to dump (OS 12214427). After making the desired modifications, which consisted of removing some DTCs related to EVAP and EGR. As well as playing around setting the speed limit to 85-90mph and AFR to 14.8.
Saving with Universal Patcher updated the checksum value at address 000714F0. However, upon flashing this to my ECU I encountered some problems. All appeared to be going well, but I saw two checksums on the ECU were now values that were not the same as the file. I was able to dump my ECU on the bench after inputting the OS version as it appears to be badly corrupted or deleted. Attempting to flash the *original bin doesn't result in any change.
*Now looking closer at everything that I have, photos, logs, etc. It would appear that I must have edited my bin file and it is no longer the exact same as from the factory ECU bin. I just noticed that the 006000-007FFF range checksum is different than the first log I have. Unless the ECU program is the one that changed if it was like a parameter or DTC that was cleared. I already ordered a replacement ECU, but some help regarding this would be appreciated as I would very much like to learn what I can about ECU programming. Thanks!