Trunk Ajar warning comes on even though trunk is shut & secure

Trunk ajar switch could be faulty . 2008 model would have a DTC - diagnostic trouble code stored if it is a electrical circuit fault . Take it to a qualified technician that has a factory or professional scanner that check these code's .

This warning light illuminates when the trunk lid is not closed securely with the ignition switch in any position.

[SOLVED] False Gate Ajar/Rear Access Open warnings: follow up post ...

forums.trailvoy.com > ... > 02-09 General Tech Q&A > General

Dec 28, 2009 - 4 posts - ‎2 authors
[SOLVED] False Gate Ajar/Rear Access Open warnings: follow up post General. ...2002 Chevy TrailBlazer LTZ ... In cold weather, I have a constant "gate ajar" warninguntil the ... Should I try to unhook/rehook the connections to the BCM? ... You might confirm it by starting the vehicle cold, see that you have ... Annoying tailgate ajar won't quit going off on 04 gmc ...
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Rear access door ajar - false signal - Fixya

www.fixya.com/cars/t22610885-rear_access_door_ajar_false_signal

There should be a switch at the trunk hinges or lid either wires are faulty or switch

Hope this helps :-)

the sensor is part of the latch so that will have to be replaced to fix it. Although water has been known to seep into the latch through the key hole (bad gasket) and fixes itself when it drys out.

Look for a contact switch in the trunk. Sometimes, when the trunk (or door for that matter) gets slammed, then button gets set deeper.
What's happening is door and trunk switches are "self adjusting", and a slam "Self adjusts" too far. It is hard to reset the switch without killing it. Just get another one if you find this to be your situation. Test the switch before you buy a replacment.

you can clean the switch , use contact cleaner , from any store for computer, or electronic parts.
If the problem persist the light is in short, replace it
God bless you

The switch is located in the latch of the trunk, make sure the wire connector to the switch is not pulled loose or otherwise damaged.

check the deck lid latch to ensure the wire harness did not get pulled off somehow... That would be the only thing I can think could cause the boot ajar light to stay on.

Yes, it has a fuse but I do not have a diagram unfortunately. Or it could be your indicator switch on the inside driver's side of the trunk. The remote will not work if the trunk is already open OR if the switch is bad/not contacting the stopper (at the base of the trunk) and falsley telling the PCM that the trunk is ajar. But if this were the problem, your should be getting a warning that your "trunk is ajar" from the onboard warning display on the guage cluster. The switch is cheesy...had to replace mine.