Please find the below information from FMB640 AVL ID list.
"Door status value: Min – 0, Max – 16128
Door status is represented as bitmask converted to decimal value. Possible values:
0 – all doors closed,
0x100 (256) – front left door is opened,
0x200 (512) – front right door is opened,
0x400 (1024) – rear left door is opened,
0x800 (2048) – rear right door is opened,
0x1000 (4096) – hood is opened,
0x2000 (8192) – trunk is opened,
0x3F00 (16128) – all doors are opened, or combinations of values".
I couldn't find the value 1028 here. Please cross check your value.
Otherwise you can create four records with each door open, So you will know the exact code for each door.
Thanks in advance