The remote locking had just stopped working on my trailblazer. I have two sets of remotes and neither of them are working with the car currently. It was totally random just came back from a trip and it wouldn't lock but had been fine the rest of that day. I have tried re-programming the remotes to the car as I was t sure if the dog standing on the door button may have caused it to disconnect somehow however this doesn't work and I have today tried replacing the remote batteries and trying to reprogam again but this hasn't worked either. The doors were locking/unlocking with the button on the door panel but this is no longer unlocking now either. The trunk doesn't have a key entry point so it currently will not open. Do you have any idea what could be wrong with it? and is this easier to do ourselves? If not, what sort of price it is likely to cost to repair it?
My car has 212720 miles.
My car has an automatic transmission.
It sounds like your vehicle has a problem with the body control module, mainly because you said the power locks are also inoperative from the door panel. The first thing I would suggest is to check the fuses, then have the body control module scanned. This might give you a fault code to work with or to help diagnose the issue. It may simply be a blown fuse. Beyond that, not much can be done without a test light, wiring schematic, and a good working knowledge of automotive electrical systems. At that point, I would recommend having the locking problem diagnosed by a professional technician.