Mechanics

THEFT SYSTEM PROBLEM

1998 Cadillac Deville

Electrical problem
1998 Cadillac Deville V8 Two Wheel Drive Automatic

Hi, Im having trouble with my 98 cadillac deville. One morning I got in my car and got the warning " theft system problem car may not restart" Iv replaced my key and lock. I do have a dead short that iv traced back to my comfort fuse in the rear hatch. Iv tried to pull codes sevral times but theres none to pull. It just reads pcm? Icm? And so forth. Wondering if I may have a pcm. Would that be causeing the short back to my battery.
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Shaloah
July 2, 2010.



" bad pcm even"

Tiny
Shaloah
Jul 2, 2010.
The PCM would not relate to a short on the comfort fuse circuit. Is the fuse blowing, or the battery going dead? When you press and hold off and warmer, it should display any codes for each module, or no XXX codes if there are no codes in the respective module. When it says PCM, and you press fan up, it should select PCM, and fan down will scroll options like PCM override, PCM codes, PCM data, etc. Highlight PCM codes and press fan up again, it should display codes. Or, scroll to VTD codes, and perform the same procedure.

Factoryjack
Jul 2, 2010.
The fuse dosnt blow it just runs the battery down. When I run the codes it just cycles through saying " no xxx codes" on all counts.

Tiny
Shaloah
Jul 3, 2010.
So after you replaced the ignition lock and key, you have no theft message, it sounds like you have no codes, so your concern is a battery drain that goes away when the comfort fuse is removed?

Factoryjack
Jul 3, 2010.
The drain with the fuse started the same time the theft messages started. It starts for about 2 seconds and dies. I replaced the key and lock but it still does the same thing. It will start for a few seconds and die. The air and radio doesnt come on ither. I originaly tracked the drain to the Body 3 fuse on the forward fuse panel and then further to the comfort fuse in the rear. Also I have a slight drain from the pull down fuse in the rear compartment. All these problems started at the same time.

Tiny
Shaloah
Jul 6, 2010.
You mention drains and slight drains, but give no specifics. On the slight drain from the pull down fuse, what is slight? Some is acceptable, around 20-30 mA. By pulling the comfort fuse, you are affecting several circuits. It supplies power to the CD changer, remote function actuation(keyless), heater and a/c programmer, and platform zone module(body control). It also powers the control side of what is called the controlled power relay. This relay is grounded by the PZM. The pull down fuse just supplies power to the pull down motor. First thing I would do, is with all circuits intact, pull the controlled power relay that is in the rear electronics bay in relay center #1. If the draw goes away, something is keeping the PZM awake. This could be somewhat complex to locate without a scan tool. Does this vehicle have aftermarket stuff installed in it, by chance. That is a major contributor to electrical problems on these vehicles.

Factoryjack
Jul 6, 2010.