2015 Chevy Suburban - Key Fob Issue

[92zman]

We have a 2015 chevy suburban 1GNSKJKC2FR663534 came in with key fobs not working and tire sensors and some lights. Checked out and could not talk to the BCM. Replaced BCM and found have to have 2 key fobs. So got one from GM then the one that was with the truck would not program to the truck. Replaced that one can get them to program but there are only really little spots inside that they will work to unlock the doors. If watching the scanner it never will say found remote. I did replace the key-less module too. No codes or anything. If you try to start it you get no key massage on the dash. Have to put in little tray for it to get it to start.

[92zman]

Does anyone know how to test the antenna for the keyless entry. Can not find it anywhere.

[ricmorin]

To confirm....
Keyless entry barely works.
Push start only works when in the tray.

Sounds like the remotes are not outputting properly. Can you check their signal strength? Also, does this have passive entry; unlock feature by simply touching the door handle?

[92zman]

No u can not walk up and it unlock. Keyfobs are new from GM and i signal is good coming out of them when u hit the buttons. There are very little areas in the car that they will lock and unlock the doors. One is in the back seat and other is up by the headliner and the sun vieser on driver side.

[92zman]

The TPMS Sensors will not program too.

[ricmorin]

No u can not walk up and it unlock. Keyfobs are new from GM and i signal is good coming out of them when u hit the buttons. There are very little areas in the car that they will lock and unlock the doors. One is in the back seat and other is up by the headliner and the sun vieser on driver side.

Just to confirm. No u can not walk up and it unlock means what? The vehicle is not equipped or it just doesn't work?

Sounds like you have to be real close to an antenna to get this to work.

[92zman]

Does not work sorry.

[ricmorin]

There are 6 different antennas, all of which allow entry and starting. It's unlikely they are all bad. Have you confirmed these are the correct remotes? Sounds like the same problem as it came in with.

[92zman]

Brand new remotes. When it came in we could not talk to the bcm so that is why it was replaced. But yes it did have this stuff wrong before too. Just found out it was at a body shop when this started. Was told then the front driver fender and front bumper was replaced. Cant see then they welded on it anywhere. Thought about pulling the fender back off just to see. Cant see any wiring being pitched off anywhere.

[ricmorin]

That's a good clue. It's possible that one of the wires for an antenna is shorted. A short could cause loss of reception. Although there is no external common wire for the antennas there may be a shared circuit internally. I may be inclined to remove the keyless entry module and check the antenna circuits for shorts to each and ground. The closest to the LF fender would be the drivers door handle antenna at the door pass through, but if it's been in an accident anything is suspect.

[92zman]

Checked no short to ground that i could find. Did find out then if i have the back door open then i can use the remote to lock and unlock the door. But if u try to start it then it will tell u still no remote found.

[92zman]

Ok found a wire going from antenna to roof to be pitched. Unpitched wire and all works great. Thanks for the help.

[ricmorin]

I'm surprised there were no codes in the keyless entry module. My theory that there is a single supply or circuit for all the antennas must be true. Glad it's fixed.

[liljoe]

Good find on this!!! Been watching this thread but didnt have anything to add of value.