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.