supra keyless start

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=132688
Printed Date: July 06, 2025 at 5:28 AM

Topic: supra keyless start

Posted By: almightyju
Subject: supra keyless start
Date Posted: November 16, 2012 at 3:23 PM

Hi everyone, I'm new, I was on allaboutcircuits.com, but it would appear I'm not allowed to talk about car stuff posted_image

so I'm hoping your all more friendly here posted_image

Basically can someone with more experience let me know what they think of my circuit? - ignore the pic I'm ok with that I'm more worried about the transistors/resistor values and if the relays will be ok.

I'm making a push start/remote start for my car (this all started from loosing my car key posted_image

), for details about the car circuit you can see the pdf here on page 55, my biggest worry is that the 50A fuse actually goes to lots of things that have a total of much more so I'm hoping a 40A relay to IG1 will be ok.

The other question is with all the switches (acc/ig1+2/ST/PINX etc) can they all run off 1 res? what happens if 2 or more buttons are pushed at once? (this shouldn't happen though), I would expect it to just draw more current but I'm not sure of the impact on the resistor. The pin buttons are just for security :)

Is there anything else I should be worried about by doing this? at the moment I'm starting my car with a screwdriver which is not ideal! so i want to somehow secure it safely.

thanks

Replies:

Posted By: howie ll
Date Posted: November 16, 2012 at 5:10 PM

Probably cheaper and much safer, inhibitors, tach learning, in gear etc. to buy an R/S and install it.
This "make it myself" comes about about every 3 months.
Forget it.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Posted By: almightyju
Date Posted: November 16, 2012 at 6:34 PM

cheaper, no, safer, only if I do things that are not safe (hence asking for electronics advise since i've not undertaken a project that needs to be fail safe), tach learning is simple its a 5v dc pulse on the non turbo supra, 4 or 6 pulses per revolution (most likely 6 since its 6 cylinders, but someone on a supra forum said it was 4...), you can then count that and calculate the rpm on a micro controller easily.

I don't mean to sound like I'm being stuck up, i've been researching this for weeks to make sure I don't do anything stupid and I think I've got it all fine electronically, I just wanted an opinion of someone experienced who can say where the flaws are or if its fine. As long as nothing bursts into flames, burns out prematurely or dies by any other beginner mistake the rest is fine as it does exactly what the ignition barrel does electronically.

I know i can buy a R/S and install it, but just what would I learn from that? I know all the theory of how to do it myself, but theories and experience are different