Hi. My first post here and I'm searchin for help with problematic 2012 model LGH Express van.

The deal is this. I did not find 100% same file from databases so I did not dare to write random file with few different parts with Flashscan without boot mode back up.
I removed ECM from the van and read it with Ktag. Reinstalled the ECM to the van and it would not start. For some reason it had lost the serial number and BCC fields and new Serial was just 1.
I removed the ECM again and read the ECM again. MPC and Flash were identical but Eeprom had some blank areas compared to the original read.
I then wrote it again and same result. Flashscan identifies TCM and ECM just fine but car wont start and the serial has changed to 1 again.
Then I noticed this thread and used Flashscan to write the original Ktag read files to the ECM and Viola! After that the serial was not 1 but at least full length code but after first ignition on cycle the freaking was again 1 and no start.
Van occasionally cranks for half a turn but usually the key just does nothing. Instruments light up some times and some times they dont seem to do anything. The glow plug and check engine light light up but are very dimm when the ignition is on.

Is there any procedure I should use or is the ECM or some other module in the van now dead? I can read, wrtie and ID the ECM just fine but for some rason it erases the Eeprom file.