FOund some other stuff. Byte_70CA bit $01 if it is set you can enter m5 without pin set.
Stock is FE, I guess if changed to FF, you will enter m5.
Too bad at one point there is a check a 607c value[ is mileage] and is compared against 8220[stock $64=100miles].
If it is over 70CA is rearmed to FE value
I suppose mileage is at least 2 words, one is lower and one is upper range.
Some eeprom examples to follow.