LT1-LT4 Modifications 1993-97 Gen II Small Block V8

lt1 restoration final steps have a bcm question

Thread Tools
 
Search this Thread
 
Old Jul 17, 2013 | 03:47 PM
  #1  
powercrazy's Avatar
Thread Starter
Staging Lane
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (3)
 
Joined: Jan 2009
Posts: 86
Likes: 0
Default lt1 restoration final steps have a bcm question

96 trans am 24x conversion installed a bcm out of a 96 z28 everything works but the car doesn't start. I know that the car and the bcm have to be synced up for the car to run. My ignition key doesn't have a resistor chip in it. So what needs to be done to have everything work at should. Thank you for the help!!!
Attached Thumbnails lt1 restoration final steps have a bcm question-img_0093.jpg   lt1 restoration final steps have a bcm question-img_0091.jpg  

Last edited by powercrazy; Jul 17, 2013 at 03:54 PM.
Reply
Old Jul 17, 2013 | 03:50 PM
  #2  
draggin97s10's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Mar 2009
Posts: 1,471
Likes: 0
Default

Solder in a resistor in the vats wire(yellow i believe) that runs down the column. That's the easy fix
Reply
Old Jul 17, 2013 | 04:03 PM
  #3  
powercrazy's Avatar
Thread Starter
Staging Lane
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (3)
 
Joined: Jan 2009
Posts: 86
Likes: 0
Default

there is no way of know what the resistance should be without the chip in the key correct?
Reply
Old Jul 17, 2013 | 04:08 PM
  #4  
draggin97s10's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Mar 2009
Posts: 1,471
Likes: 0
Default

Originally Posted by powercrazy
there is no way of know what the resistance should be without the chip in the key correct?
I'm sure there is, but I cannot tell you how to figure that out. There is a range of them. I think we just bought 4 or 5 and Swapped them until one worked. Someone could tell you the range of resistors that worked or you could find it somewhere.

Sorry i'm not being much help.

On a buddies car we tested the key and did it that way.
Reply
Old Jul 17, 2013 | 05:55 PM
  #5  
ltxMonte's Avatar
Teching In
 
Joined: Jul 2013
Posts: 5
Likes: 0
Default

The resistance for the vats are: 402, 523, 681, 887, 1130, 1470, 1870, 2370, 3010, 3740, 4750, 6040, 7500, 9530 and 11800. Since you don't have the chip for the key, you will unfortunately have to build all 15 and try them. A bulk pack for radio shack runs like $15 and has all the values to make them many times over.
Reply
Old Jul 17, 2013 | 06:01 PM
  #6  
powercrazy's Avatar
Thread Starter
Staging Lane
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (3)
 
Joined: Jan 2009
Posts: 86
Likes: 0
Default

ok thank you very much once I find the correct value the car will start with the z28 bcm there is no other way such as with a tech 2
Reply
Old Jul 17, 2013 | 09:53 PM
  #7  
SoxXpupPeT's Avatar
TECH Junkie
iTrader: (34)
 
Joined: May 2008
Posts: 3,431
Likes: 1
From: Yonkers, NY
Default

Or just tune it out of the ecu. OP your car looks SICK!
Reply
Old Jul 18, 2013 | 12:59 AM
  #8  
BizZzatch350's Avatar
Moderator
20 Year Member
Photogenic
iTrader: (33)
 
Joined: Dec 2001
Posts: 9,793
Likes: 15
From: T E X A S
Default

My 93 didn't have a BCM so I never had this issue, but clean Trans Am
Reply
Old Jul 18, 2013 | 08:48 AM
  #9  
xBrandonx's Avatar
TECH Regular
10 Year Member
Photogenic
Photoriffic
Liked
iTrader: (11)
 
Joined: Feb 2011
Posts: 441
Likes: 9
From: Reading, PA
Default

Here's a pre-made bypass, http://www.ebay.com/itm/Vehicle-Anti-Theft-System-VATS-Bypass-Keycode-12-/281122283221?pt=Motors_Car_Truck_Parts_Accessories&hash=item4174319ed5&vxp=mtr
Reply
Old Jul 18, 2013 | 09:18 AM
  #10  
draggin97s10's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Mar 2009
Posts: 1,471
Likes: 0
Default

Originally Posted by ltxMonte
The resistance for the vats are: 402, 523, 681, 887, 1130, 1470, 1870, 2370, 3010, 3740, 4750, 6040, 7500, 9530 and 11800. Since you don't have the chip for the key, you will unfortunately have to build all 15 and try them. A bulk pack for radio shack runs like $15 and has all the values to make them many times over.
There you go! That is what I did. and then
Reply
Old Jul 18, 2013 | 04:31 PM
  #11  
powercrazy's Avatar
Thread Starter
Staging Lane
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (3)
 
Joined: Jan 2009
Posts: 86
Likes: 0
Default

Originally Posted by draggin97s10
There you go! That is what I did. and then
I like that piece that is on eBay but my key doesn't have a chip in it and the bcm is out of another car. So I need to find out what resistance that bcm is looking to see. So I guess the try one resistor at a time unless there is a way to test what that bcm is looking for. Appreciate the advice everyone.
Reply
Old Jul 19, 2013 | 09:42 AM
  #12  
nitrous2fast's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Dec 2010
Posts: 1,084
Likes: 0
From: Oklahoma
Default

If you had a potentiometer and a multimeter you could find out decently quick. Don't know if it would be faster or not.
Reply
Old Jul 21, 2013 | 04:34 PM
  #13  
ltxMonte's Avatar
Teching In
 
Joined: Jul 2013
Posts: 5
Likes: 0
Default

You can tune the vats out of the pcm, but not the bcm, which kills the starter. I don't know that the other way would be any faster...
Reply




All times are GMT -5. The time now is 12:15 AM.