So my alarm goes off every time you open the door. I tried removing the bcm fuses and then when i went to restart it now the locked car is solid doesnt go off. I have 2 keys noth do same no working ley fob. I have tried the relearn with no avail. Any one have any ideas plz help me thanks

 

Does your key fob not work at all... or does the unlock/lock not work?

My unlock/lock buttons wouldn't work, but the trunk and alarm buttons still worked. This issue is that there are conductive pads on the backsides of the fob's buttons, and they become less and less conductive over time, until they eventually don't conduct at all and the button will no longer work. I remedied this by super gluing aluminum foil to the back of the pads. It's a super elegant solution.

Alternatively, the receiver in your car is busted. No easy fix.

 

yes i have key fob none of any buttons work i dont know my car started yesterday then i was trying to get the alarm to stop when ibpulled the bcm fuse but when ibput it back in now the car it wont turn the fuel pump on so its in anti theft mode i guess no way out of this without a key fob or wht is the possible fix

 

Disconnecting the BCM was potentially a bad move. The PCM and BCM communicate with each other. My understanding is that any interruption while they are powered will cause issues.

I assume you've put a new battery in the FOBs, right? I would try to verify if the FOB's are even working. The issue that I mentioned is common issue #1, while common issue #2 is that weak solder/connection where the battery mounts to the board.

 

Well unfortunately i guess the ecu is bad cause obd2 is having problems communicating withe ecu so hopefully the repair of ecu will be it i had a locksmith chk my keys are good and my key fob he says is good

 

Food for thought, not sure if its part of your issue. I experienced similar alarm going off on a friends LSJ (06 I think) every time he used the key even if he manual locked the doors, the FOB had been lost by one of the previous owners. In addition to the missing FOB the passenger lock and window buttons were not working, he pulled one from the local pull-n-pay and after installing the alarm stopped going off when he used the key.

I'm not sure of the service manual lists how to test all the circuits for the doors/trunk to verify all the switches are communicating to the BCM. But you might manually check function of the various door/window/trunk switches, thats in addition to your other trouble shooting for the ECU/BCM issues you're dealing with.

 

Thxa for the info at the moment my door locks and windows noth work on both doors and from what i know lock smith scanbed the car and it was a b1000 code sonething for loss of communication with ecu aswell i was trying to rewrite the ecu with hptuners and it was failing to communicate so i ordered a used but vin programedbecu thats plug and play so fingers crossed its this and not a shorted wire on the harness

 

So i installed a new programmed pcm for my lsj i did the key learn and then i had to do a crank relearn on hptunerz. I did all this car ran and drove great but i am still dealing with its stuck with the alarm system on put key into to start the car withlock stays on i have tried the 30min and 3 10mins security resets nothing os getting my car out of this security Mode honestly im so aggro about this i even got a new battery to try and fix this i ha e tried reading 1000 differe t threads on bypassing the system but thrs nothing involving the cobalt that i have found im asking for anyone who has hade this problem and fixed it or has good input to help me out. I really trying to avoid a 1000 bill at dealership for them to temperary fix my car