Key fob and alarm issues

2011 GMC TERRAIN

164,050 MILES • 2.4L • 4 CYL • 4WD • AUTOMATIC

CH1989

MEMBER
2 POSTS

I have a key fob that is able to lock the doors but not unlock due to the button being broken. when I unlock the doors manually it sets off an alarm until I start the vehicle. even locking the doors manually inside the vehicle, it sets off the alarm when unlocking it. what is the issue?

Feb 28, 2018 at 9:30 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Hello,

If the fob button is broken this can be the cause of the security system confusion. If the button is not stuck down my next step would be to replace the drivers door latch because the micro switch inside the latch goes bad causing the system to think the door is open all the time does the interior lights come on when the malfunction is happening?

Test the switches int he doors by following this guide

https://www.2carpros.com/articles/how-to-check-wiring

and check out the diagrams below for the security system so you can see how the system works.

If everything checks out all trails lead to the BCM which when you replace it it will need to be programmed in.

Check out the diagrams (Below)

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
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Mar 2, 2018 at 11:08 AM