Help with my 2003 Trailblazer LS 4.2 issues

I just got this Trailblazer a week ago and it was running fine until recently. My driver side door doesn’t have the window/door lock control panel, so I’ve been locking the driver side manually and using the remote for the other doors. The other day, I unlocked the driver side with the key and forgot to hit the unlock button on the remote for the others. When I tried to start it, the alarm went off. I pressed the unlock button to stop the alarm, but then the security light started flashing and I couldn’t start the car. I managed to reset the security system and got it going again. I thought I needed to use the remote to unlock it before starting, but now it’s happened again even though I’ve had it unlocked for two days. I can reset it, but I really want to fix this issue completely. Any suggestions would be greatly appreciated. Oh, and I have the control panel for the door lock and windows, just haven’t had time to install it yet.

You should definitely install that control panel. It might help with the communication with the BCM, which could be causing your issues.

Gray said:
You should definitely install that control panel. It might help with the communication with the BCM, which could be causing your issues.

I’ve been meaning to do that. Do you think it would fix the security light problem?

@Jesse
Yeah, I think it would help. Those controls are more than just switches; they communicate with the system.

I had a similar issue with my Trailblazer. It turned out to be a wiring problem. Have you checked the wiring in the door?

Dane said:
I had a similar issue with my Trailblazer. It turned out to be a wiring problem. Have you checked the wiring in the door?

I haven’t looked at the wiring yet. I’ll check that out next. Thanks for the tip!

Sounds frustrating… maybe try resetting the battery? Sometimes that clears up weird issues.

Frost said:
Sounds frustrating… maybe try resetting the battery? Sometimes that clears up weird issues.

That’s a good idea. I’ll give that a shot and see if it helps!

For the security light, make sure there’s no obstruction in the door locks. Sometimes debris can cause it to think the door is still locked.

Whit said:
For the security light, make sure there’s no obstruction in the door locks. Sometimes debris can cause it to think the door is still locked.

I’ll check for that too. I didn’t even think about it getting stuck.

Good luck with the fix! Keeping up with these little issues can be a pain, but you’ll get it sorted.

Azar said:
Good luck with the fix! Keeping up with these little issues can be a pain, but you’ll get it sorted.

Thanks! I appreciate the support. Hopefully, I’ll have it all figured out soon.