98 alarm stays on & engine cuts out. New ignition. No original keys except Valet. Did not have problem at first. Vehicle has been setting several months. Battery has been disconnected and replaced, also disconnected to recharge. Anything? Thanks.

 

Your vehicle security system is purposely turning it off. Every time you disconnect the battery it’ll go into like a security mode. So disconnect your battery, reconnect it and then unlock your passenger side door and this should work just fine.

 

my 2000 was bought as an abandoned vehicle from a shop.
So after replacing the engine, I had a key issue.
In short I sent off the ECM to have a SKIM delete,
Disconnected the skim, and it worked sorta,
But alarm kept going off. I finally bit the bullet.
Called a locksmith, new chip key, reflashed for the new keys.
$150 later....
No more issue, been 2+ years now.
When I asked WHY,
if the BCM does not see the correct VIN in the PCM,
it assumes something is not kosher and will activate the alarm.
Typically SKIM fault means only starts for 3 seconds then dies again.