ECU Coding for lights n stuff

[ArtfulHussy]

Does anyone have much knowledge of writing custom codes for ECUs? My question is sort of in general at the moment, and I'm struggling to find info online as I'm unsure I'm using the right search words.

I just wondered if it is possible to write custom codes for your ECU to do things like auto-lock doors at a certain speed, switch on headlights/puddle lights when the central locking is unlocked and such. Things that are becoming more common on modern cars that are nice little perks.

 

[Ian G]

Would be the GEM unit that locked the doors although I'm not sure it has a speed pulse in there. And also whether it is in any way programmable.

Easiest way to have speed locking would be to replicate the microswitch input from the lock barrel, ie. put a relay in parallel with the microswitch and have that fire instead of the switch. That way the GEM would think the key in the barrel has commanded the lock motors when in fact it was something else that closed the circuit. Either way the GEM won't care.

Speed pulse is in the ECU loom and you'd need to smooth that in to DC from a pulse which again not a simple thing but fairly well documented.

Headlights on unlock again, you have unlock line in the door barrel switch, that just needs to trigger a timed latch and you could power stuff with that.

All possible but I would guess not without some hardware.

 

[ArtfulHussy]

Thanks Ian. Just stuff I'm thinking about before I get into restoring my 1.7 to be a daily. It'll be stripped to a shell, engine rebuilt etc, so if it's possible to pursue this sort of upgrades I'd want to make the necessary additions whilst it is easiest to gain access. Can you advise what sort of literature I maybe need to be looking at in order to better understand these things? Car electrics/electronics are a totally alien world to me. I'm sure there must be a forum somewhere dedicated to this kind of wizardry!