LCD display that warns if the door is open is not working properly

JUSTAGRLWITHACAR

MEMBER
2008 PONTIAC GRAND PRIX
3.8L
V6
2WD
AUTOMATIC
135,000 MILES

Yesterday, my husband was driving my car and the front LCD display that tells when a door is open started weirding out. While my husband was driving it started flashing that the emergency brake is on, it's registering that the doors are open, and that we need to check tire pressure. He gets home and parks it and two hours later the horn starts blaring and won't stop. We ended up having to disconnect the battery to cease the constant horn blaring. I left the battery unhooked all night. Next morning I reconnected the battery cable and the horn immediately started blaring again. Disconnected the fuse for the horn and now the headlights are blinking and the doors keep locking and unlocking. We don't know where to even begin. I am a college student, there fore we do most of our own mechanic work. Please help : /

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Let's start with the LCD and door ajar issue and the current issue of the locking and unlocking of the locks. You have an issue with the BCM. I attached the info about this module. Basically it controls all the systems related to the body of the vehicle including lights, locks, cluster, door ajar and more. See the attachments for the detail on everything else.

What happened is you have an issue with the BCM and when you turned off the vehicle and locked it, the BCM unlocked the locks or triggered the door ajar system and the alarm system thought someone was breaking in and it triggered the alarm.

At this point, you are going to need to replace the BCM and have it programmed if you don't have a scan tool capable of doing the procedure. It is all attached for your review.

Please reach out with questions. Thanks

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