Originally Posted by
Speedy4x4
65,535 starts, so if I keep it at 20 starts a week, I should be good for 63 years, sweet, makes me feel better
I wish there was a cost effecient way to get rid of skreem, and all security.
keys just need cut and no rfid.
if I want to unlock doors, a separate stand alone system.
If I want a alarm, another separate system.
Ecu only has one job, make the car run, cruise control and gauges, as almost a stand alone system.
LEDs issues, less problems, more reliable.
The 65,535 are estimated by me (2 bytes) maybe the code length which the skreem sends to the PCM also limits the number (8 bytes).
A rolling code system normally works in such a way that there is a secret and a formula that both parties (Skreem and PCM) know and a consecutive number.
This is how the simplest form looks like:
Code = Secret + Sequential number.
But since this would be much too easy to crack, the formula is more complicated, e.g:
Code = (Secret + 14 + (Consecutive number * 4)) /2
The consecutive number prevents codes from being easily intercepted and reused.
Only codes with a number that are higher than the last one used will be accepted.