Check to see if the security light is on. Sounds like you have an antitheft mode problem. If you can jump it on the starter but not at ignition, sounds like the security is blocking you.
If there is a light on your dash that says security when you put the key forward, read this info.
So the Security light is on or flashing in your vehicle and you are looking at 1 of 3 things. Either the vehicle won't crank over and start, It cranks but dies in a few seconds, or your vehicle shuts off while driving scaring the **** out of you. You have now experienced GM's worst security system ever created. GM's security, also known as Passlock Passkey or Vats.
There are 3 parts in this system.
Normally a black resister chip in key which "communicates" to the lock cylinder. Sometimes is hidden in the plastic part of keys in new models. Same concept, might say PK1 PK2 PK3 PL or something similar to that. The newer ones work on frequency. Same thing tho.
2.The LOCK CYLINDER
Inside there are pins that read the chip in the key or the part that reads the frequency on new models. This then "communicates" to the TDM)
Theft Deterrant Module-Sometimes called the "computer" or "brain". This is the part that sends the signal (**NOTE**) to your car and allows your car to start or continue running depending on your type of system.
If any of these parts are not communicating properly, your SECURITY light will come on and shut down your vehicle. The idea being, that without the chipped key or FOB key, the vehicle wont start and cant be "hotwired" or stolen. Pretty nice when working, but these systems are flawed and the average life is 6-10 years. Every single aspect of this system is expensive to replace and can only be worked on by "authorized" GM service men with out voiding warrenty. Most garages dont even touch them and if they do,
they will sell you every part they can before "fixing" the problem/
*QUICK FIX TRICKS*
Try a spare key that is newer or used less. The pins wear down with use and so do the keys causing the security to fail.
(if not starting) turn the key forward 2 clicks till right before it would normally start, leave like that for 10 minutes. ( no less ) After 10 minutes, turn key back then forward and your car might start. I did this in my Buick for more than a year. If its shutting down while running, I'm sorry I have no quick fix...
Well since the lifespan of these systems are so short, and are extremely expensive to fix, and in my opinion far worse of a threat to owners than theives, my only perminant suggestion is to eliminate it completely. After a year of 10 minute tricks and a "key bypass" that lasted 2 months and stranded me out of state, ($375 tow charge) i have only one good suggestion. After surfing the web for hours thru forums and websites i came across http://newrockies.com/passkey
to the starter or injectors and so on. Thus eliminating the ENTIRE system completely. I came upon a fork in my road. A TDM for $600 in my $1000 car or the $200 bypass. Or throw my car away. Lets say i now drive a Buick with the chip ripped out of the key and the TDM sitting in my glovebox for show
and tell. If you have any questions or anything else. Comment on this post
and i'll get an E-mail to reply to you. If you do choose to buy the bypass,
i have pictures of what a TDM looks like and will definately help you when
installing the newrockies bypass. Good luck
Here is a list of known effected cars that can be fixed with the
newrockies bypass. This is the same list from the site and updates
2003-2007 Hummer H2
1994-2003 Grand Prix
1996-2005 Grand AM
1994-1998 Trans Sports
1996-2002 Trans Am
1991-1996 Park Avenue / Ultra
1991-1996 Roadmaster Estate Wagon
1982-1990 Electra (all models)
1991-1993 Delta 88
1994-1997 Cutlass Supreme
1991-1996 Custom Cruiser
1995-2005 Monte Carlo
1994-1996 Caprice/Caprice Wagon
1995-1996 Impala SS
1997-2005 Malibu Classic
1985-1996 Fleetwood Brougham
1994-1995 Deville Concours
1994-1995 ElDorado Touring