Service theft system

I have a 2003 cadillac deville dhs.I have changed the battery and alternator and it still say low battery voltage service theft system. They radio and dash lights go on and off and want crank.What do I need to do.

Did you ever fix it

I'm having the same problem with my deville...somebody said use the key and lock?

I have a 2005 Cadillac Deville DTS it won’t turn over, cleaned the ground connection to the engine block changed the ignition switch,fuel pump starter relays ignition relays and fuse The car still will not crank over, I have a brand new starter but I’m hesitant to install because when I ground the terminals for the starter it turns over, if I turn the key the Dashboard will blacks out/ short. Please any Advice

I have a very similar problem my 2001 base model DeVille says service theft system the car would not turn over (at first)it's not a battery issue clearly it's something to do with the theft system however the valet key did start it, (thank God or stranded I would be) my other alternate driver key does start it and now the original key starts it but after clearing codes the service theft system indicator came back up on the dash and I'm just wondering if anybody has any clues.if anybody needs I will certainly report my codes just want to see if this thread is still active or if anybody still looking. Thank you for your time

How did you ground the starter to get it to turn over