My next winter project---push button start
Thread Starter
Safety Car
Joined: Jan 2001
Posts: 4,996
Likes: 504
From: Hilton NY
My next winter project---push button start
My '98 already has fob passive recognition and the computer prevents restart when the engine is running so this shouldn't be too difficult. Just as the schematics show, the car passed the first test this morning; while the engine was running, the starter wouldn't energize. I have another car with this feature and like it a lot, the key is only for an emergency and can be carried in a wallet. First a start switch needs to be selected and then the design will follow. The key resistance reader will be replaced with a small solid state relay and correct value resistor, if extra security is desired then a hidden switch can break this circuit. Redundancy will be designed in so that the car won't fail to start and run. As the car is designed now if the key resistance reader fails then the car won't start, I had this happen on another GM car which had to be towed to the dealer where the reader was replaced. I'll post some pictures as the parts go together.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Another subject that's been beaten to death. There have been many postings on this and most people never really did it. Seems the electrical system (especially with the column lock) is touchy enough already-adding to this mess is asking for trouble-but have FUN if you want for no apparent upside.
Supporting Vendor
Joined: Jul 2010
Posts: 8,547
Likes: 896
From: Republic of Texas
The biggest issue is getting the computer to remotely recognize the Vats for startup. Here's what i'm thinking:
1) identify the Vats resistor value, find a resistor of exactly that value
2) You will need two switches, a master "ARM" and momnetary pushbutton switch for the ignition. The Arm switch will allow you to start and shutoff the engine and the pushbutton will actually crank the engine.
3) The momentary ignition button will replace the "key start" in the ignition circuit. The Arm switch will replace the locking portion of the ignition cylinder circuit.
4) The door-lock circuit will need to be tired into the Arm switch via a series of relays. The idea is that the Arm switch does NOT get power when the car is locked. When the car is unlocked, the switch gets power tripped from a secondary power source that allows it to remain "on" reguardless of the door locks until the switch is turned off.....otherwise your car will die anytime you lock the doors
this could also be done with a seperate wireless 12v remote setup, or bypassing the door lock feature entirely and just hiding the Arm switch (running constant power to the switch and just hoping nobody finds it)
1) identify the Vats resistor value, find a resistor of exactly that value
2) You will need two switches, a master "ARM" and momnetary pushbutton switch for the ignition. The Arm switch will allow you to start and shutoff the engine and the pushbutton will actually crank the engine.
3) The momentary ignition button will replace the "key start" in the ignition circuit. The Arm switch will replace the locking portion of the ignition cylinder circuit.
4) The door-lock circuit will need to be tired into the Arm switch via a series of relays. The idea is that the Arm switch does NOT get power when the car is locked. When the car is unlocked, the switch gets power tripped from a secondary power source that allows it to remain "on" reguardless of the door locks until the switch is turned off.....otherwise your car will die anytime you lock the doors
this could also be done with a seperate wireless 12v remote setup, or bypassing the door lock feature entirely and just hiding the Arm switch (running constant power to the switch and just hoping nobody finds it)
Safety Car
Joined: May 2004
Posts: 4,628
Likes: 397
From: Madison Wi
IMO your test of the starter was inadequate.
I agree that the car prevents the starter from being engaged once the engine is running.
BUT I'm 90% sure it does not shut off the starter once the engine fires if you hold the key in the start position. The starter will continue cranking until you release the key.
My Mother-In-Laws's 2005 Buick LaCrosse DOES shut off the starter automatically if you hold the key in the start position. In fact, on that car all you have to do is twitch the key to the start position for a millisecond and the engine will start on its own after you release the key.
I do not believe the C5 computers have this logic built into them, however.
In order to accomplish what you want you'd need to purchase an aftermarket remote vehicle starter and wire it in with a start button on the dash. That would allow it to reference a tachometer input to know when to disengage the starter motor.
I agree that the car prevents the starter from being engaged once the engine is running.
BUT I'm 90% sure it does not shut off the starter once the engine fires if you hold the key in the start position. The starter will continue cranking until you release the key.
My Mother-In-Laws's 2005 Buick LaCrosse DOES shut off the starter automatically if you hold the key in the start position. In fact, on that car all you have to do is twitch the key to the start position for a millisecond and the engine will start on its own after you release the key.
I do not believe the C5 computers have this logic built into them, however.
In order to accomplish what you want you'd need to purchase an aftermarket remote vehicle starter and wire it in with a start button on the dash. That would allow it to reference a tachometer input to know when to disengage the starter motor.
Last edited by TraceZ; Oct 6, 2010 at 12:55 PM.
Supporting Vendor
Joined: Jul 2010
Posts: 8,547
Likes: 896
From: Republic of Texas
One of the guys in the Sam houston Covette club has a push-button installed on his car, but it's part of an aftermarket remote start system. He has to carry an extra FOB with him.
Imo, the only way a push button start will make ANY sense for convience is to use an aftermarket remote start system and do away with the factory FOB.
Imo, the only way a push button start will make ANY sense for convience is to use an aftermarket remote start system and do away with the factory FOB.
Race Director
Joined: Aug 1999
Posts: 11,117
Likes: 671
From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
Remote starter ?
I'm not one to look negatively on someone elses mods, Every bodys are different. But this seems to be one where the "Chase is not worth the run !"
But hay, if you like it, go for it my friend.
But hay, if you like it, go for it my friend.
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
You still have to use the key to unlock the steering column... what sense does it make to turn the key to unlock the wheel (but don't start) and then reach somewhere else to push a cobbled-up starter switch? 
Sounds like another C5 quickly on it's way to being a chopped up C4.
Sounds like another C5 quickly on it's way to being a chopped up C4.
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Thread Starter
Safety Car
Joined: Jan 2001
Posts: 4,996
Likes: 504
From: Hilton NY
I've had good luck so far with an A4 shifter, trunk pull down, led sweep lights, etc, and feel that this isn't as difficult as some might think. I'll find out if it works or not, either way something will be learned by trying. #1 and #4 are easy. One push button switch should be able to sequence power from ACC then one second later to IGN then one second later to Start all with one push. Another push while in Park or Neutral reverses the sequence to turn off IGN power then one second later to turn off ACC power.
Safety Car
Joined: Jun 2009
Posts: 3,888
Likes: 2
From: Frederick, Maryland
This is one mod I do want done hands down. I have a remote starter on my Cadi and love it. A performance shop across the street from me had a push button kit, but I dont trust them with my vette. One thing my cts has is you take one of your keys(or have another made) and put it in the "bypass box". Th key is surrounded by an electromagnet which reads the info and makes the system think the key is in the ignition. Sadly I cant remember what company makes the sytems. Its "X" something lol
Good luck with this mod!I can tell you know what your doing
I forgot about the one I wanted most! lol
Good luck with this mod!I can tell you know what your doing
I forgot about the one I wanted most! lol
Indy
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
All you have to do to make VATS happy is hack in a precision resistor the same value as the pellet on your key. Still seems like an adventure with much pain involved for no real upside except making your car start like a 1940 pickup truck with a push button starter.
Wonder how many people would want to buy one of these hacked up cars. I know I would stay far away from an Electrically hacked up C5 Vette.
Wonder how many people would want to buy one of these hacked up cars. I know I would stay far away from an Electrically hacked up C5 Vette.
Le Mans Master
Joined: May 2006
Posts: 7,851
Likes: 236
From: Hillsboro OR
Another subject that's been beaten to death. There have been many postings on this and most people never really did it. Seems the electrical system (especially with the column lock) is touchy enough already-adding to this mess is asking for trouble-but have FUN if you want for no apparent upside.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
I do, where's your BOWL? 
Silly mod, why waste your time and hack up a perfectly good car. Again, search on this-beaten to death before-I would never buy a car where someone has hacked it up like this and anyone that does is ASKING for headaches.
Silly mod, why waste your time and hack up a perfectly good car. Again, search on this-beaten to death before-I would never buy a car where someone has hacked it up like this and anyone that does is ASKING for headaches.
Melting Slicks
Joined: Dec 2003
Posts: 2,857
Likes: 2
From: pawleys island sc
One of the guys in the Sam houston Covette club has a push-button installed on his car, but it's part of an aftermarket remote start system. He has to carry an extra FOB with him.
Imo, the only way a push button start will make ANY sense for convience is to use an aftermarket remote start system and do away with the factory FOB.
Imo, the only way a push button start will make ANY sense for convience is to use an aftermarket remote start system and do away with the factory FOB.
that's just what i need -to carry an EXTRA key. Maybe I can find a push button start the requires me to carry a hand crank - that would really be cool.