Engine crank with button

I am going to go looking for that YEL/BLK wire in the BCM that was previously mentioned. What seems so odd is that I dont see anyway that the alarm is connected to the YEL/BLK or even controlls it somehow but it still auto-starts? Just seems weird that I would have to connect to that wire but it didn't? John

WOOO HOOO! When pushing in the clutch, hitting the button, and giving ground to the previously mentioned YEL/BLK wire in the BCM, THE CAR FREAKIN' STARTED!! I did not need to trip the VATS by-pass relay so it read the resistor from the key. The smile on my face went from ear to ear. BIG TIME THANKS TO djfearny2 FOR MENTIONING THIS WIRE AND TO Mad Scientists for their input on this! I still don't understand why the auto-start alarm can start the car without having to tie into this wire? It appears the YEL/BLK wire is tied to the theft deterrent relay so how is the alarm able to start the car? John

calee4nyaboy wrote: WOOO HOOO! When pushing in the clutch, hitting the button, and giving ground to the previously mentioned YEL/BLK wire in the BCM, THE CAR FREAKIN' STARTED!! I did not need to trip the VATS by-pass relay so it read the resistor from the key.

 The reason it cranked is because you grounded the yellow/black wire.. I don't know if it read the key or not, but by grounding the yellow/black wire you've bypassed the antitheft component of the vehicle security system. This means that you could probably start the car with a duplicate key that doesn't have a security pellet in it.

calee4nyaboy wrote: The smile on my face went from ear to ear. BIG TIME THANKS TO djfearny2 FOR MENTIONING THIS WIRE AND TO Mad Scientists for their input on this! I still don't understand why the auto-start alarm can start the car without having to tie into this wire? It appears the YEL/BLK wire is tied to the theft deterrent relay so how is the alarm able to start the car? John

 Evidently the auto-start is meeting all the requirements of the vehicle anti-theft system and thus, the car starts.

 What exactly you are missing, I don't know... is how you've got it now ok, or do you still want to 'do it right'? If you can borrow a scan tool (this is what I use)

http://buy1.snapon.com/catalog/pro_det.asp?P65=&tool=diagnostics&item_ID=67130&group_ID=17428&store=snapon-store&dir=catalog

 you can probably figure out why the anti-theft system doesn't like your pushbutton approach.

 Jim

When I said I wanted to do it right, I merely meant with the button and a relay or two (since thats all it should take) What I did NOT wanna do is go through the hassle of going under the hood directly to the starter having to use big fat wires due to high amperage conditions etc etc. I consider this "done right" and am very happy about it but if you consider the following I am still confused: The alarm ties into the following wires in order to auto start the car: ACC IGNITION 1 IGNITION 2 STARTER (CLUTCH WIRE) VATS When using the push button: With the key in the RUN position, I have tested that the ACC and IGNITION 1 & 2 receive 12v. The button gives 12 volts to the same clutch wire (also tested with volt meter) and the VATS was not necessary to alter because I found that it did in fact read the resistor pellet when the car successfully cranked with the button. This is why it drove me crazy. There are very few wires, all easy to hook up and test and when I emulated them, it didnt work. And now i have to go to some tiny gauge wire that by-passes the starter kill? You can see why that doesnt make any sense...lol Don't get me wrong, I'm really glad it works, but I dont like for it to just work, I like to understand (for my own knowledge and experience) what is going on and what the difference is etc. I still dont see where the difference is and how the alarm with its simple wiring can pull it off without needing that YEL/BLK wire. If I was the kinda guy that didnt care about all this stuff I would have just taken it to some shop and paid them to do it. I'm sure I'll do more stupid and useless things like this in the future and I was just hoping this experience would help me learn from it. As far as the scan tool, 7 grand is a bit much for me to spend. : ) John

calee4nyaboy wrote: When I said I wanted to do it right, I merely meant with the button and a relay or two (since thats all it should take) What I did NOT wanna do is go through the hassle of going under the hood directly to the starter having to use big fat wires due to high amperage conditions etc etc.

 

 Simple would have been to take the pushbutton, one side wired to +12v, the other side to the purple wire off the theft deterrent relay.

 Press button, engine cranks.

calee4nyaboy wrote: I consider this "done right" and am very happy about it but if you consider the following I am still confused: The alarm ties into the following wires in order to auto start the car: ACC IGNITION 1 IGNITION 2 STARTER (CLUTCH WIRE) VATS When using the push button: With the key in the RUN position, I have tested that the ACC and IGNITION 1 & 2 receive 12v. The button gives 12 volts to the same clutch wire (also tested with volt meter) and the VATS was not necessary to alter because I found that it did in fact read the resistor pellet when the car successfully cranked with the button. This is why it drove me crazy. There are very few wires, all easy to hook up and test and when I emulated them, it didnt work. And now i have to go to some tiny gauge wire that by-passes the starter kill? You can see why that doesnt make any sense...lol Don't get me wrong, I'm really glad it works, but I dont like for it to just work, I like to understand (for my own knowledge and experience) what is going on and what the difference is etc. I still dont see where the difference is and how the alarm with its simple wiring can pull it off without needing that YEL/BLK wire. If I was the kinda guy that didnt care about all this stuff I would have just taken it to some shop and paid them to do it. I'm sure I'll do more stupid and useless things like this in the future and I was just hoping this experience would help me learn from it. As far as the scan tool, 7 grand is a bit much for me to spend. : ) John

 I think that if you probed the theft deterrent relay you'd find that the car didn't crank because the computer (BCM) didn't allow it. I don't know why, but I'd bet on either the factory anti-theft system or the anti-grind feature.

 A good scan tool could probably tell you why the BCM locked out the starter.. (if that's the problem)..

 How are you verifying the VATS system is working properly?..  You've mentioned a couple times that you knew it wasn't the problem, but how are you determining this?

 How does the auto-start system interface with the VATS system?.. you mentioned that the auto start is wired to the VATS system.. how?

 What make/model is the auto start?..

 Regards,

 Jim

Jim, I totally agree with you that it has something to do with the theft deterrent system/relay. Probably because the VATS is not giving it the "OK". If this is the case, why the VATS is not giving the OK is what is troubling me. The car is an '02 Corvette and the alarm is a Compustar 2WSS-AS. When using just the key to start the car, it starts fine because it read the resistor pellet. When using auto-start, it also works fine because I tied a VATS by-pass relay in with the alarm to read the proper resistance of the pellet (using a dummy resistor of the correct value). When using the button to start the car, the key is in the RUN position, the button is pressed (which gives the purple clutch wire 12v and the YEL/BLK wire at the BCM a ground via 2 separate relays) and the car starts. Because the VATS by-pass relay was NOT touched in anyway or energized when using the button, I figured the car read the resistor pellet...UNLESS giving the ground to the YEL/BLK wire by-passed the VATS system altogether making it not need to see any resistance what-so-ever. But since I suspected that it might be the VATS giving me a problem (before I ever messed with the YEL/BLK wire) I tested the system as follows with still NO LUCK: 1) key in run position 2) press clutch in 3) energize VATS by-pass relay so I KNEW the car was seeing the resistance it wanted (I did this because I did not know if the car was reading the key or not in the RUN position) This step should have taken care of any theft deterrent issue like the YEL/BLK wire. 4) press button (giving violet clutch wire 12v) If you think about it, this is EXACTLY what the auto start alarm does in order to start the car. The exact sequence of how my alarm starts the car is as follows: 1) it energizes the VATS by-pass relay 2) it gives 12v to ACC and both Ignitions 3) it gives the yellow clutch wire 12v **car cranks** It's such a simple procedure and I dont see the difference between the two? John

If it is working the way you want it, leave it. But I have installed a few remote starters, and have had this problem.. somewhat. When you start your car, you insert the key and go from off, on some to acc, then to gear shift unlock (on auto vehicles), then to on. When you go one step further, it goes onto the momentary *start* position. When the key is on the start position, the switch takes away power from all accessory lines. Now if you dont do this right, and you try to start with the accessory lines still powered, it may not let the car start. Ive seen that a few times. I then put relays in to cut accessory power when Starter wire is positive. That made the car start right up. But this was my bit of advice or something. LOL..