1998 pontiac gran am code help

ive been trying to figure out the odes on my sister car..ever where I look I cant find any of them ...if any of you guys can help it would really help...

the codes are

b1236
b1257
b1265
b1262
b1286
the car just started killing the battery over night ..se don't drive it much but she does need it as she is disable ...so im trying to help her out ...thanks for any help... im still on the we trying to find out some info on them