Manager Forum

I've got a 2005 GMC 2500HD with 6.6 Duramax. This just so happens to be my own truck.

It has remote locks and the remote will lock but will not unlock the doors. The door lock switches both unlock the door without problem. It has no codes in any module. If I program the remote it will start working but only for a few unlocks then it's back to not working.

It is not the remote, when viewing the passenger door module, this is the module that handles the remote locks, with scan tool it shows that it sees the fob is unlocking the door but it actually does not unlock.

My thoughts are that it is the passenger door module. Am I overlooking something? Is there something else I need to look at that I'm not thinking of?

A year or so back it did this same thing and one day it just started working and it worked for a long time.

Do you have a tool that can test the signal coming out of the remote. If you do I would do that first (just to check). Then I would try unplugging the door module and waiting a min then plug it back in. We get a/c module that mess up all the time and that will fix them for a while. If that does work you will need a module but it will tell you for sure what is wrong.

92zman wrote:Do you have a tool that can test the signal coming out of the remote. If you do I would do that first (just to check). Then I would try unplugging the door module and waiting a min then plug it back in. We get a/c module that mess up all the time and that will fix them for a while. If that does work you will need a module but it will tell you for sure what is wrong.

We do have a tool for checking remotes and it checks OK. The module sees the remote being pressed on the scan data so it seems like the remote would have to be working.

I have unplugged the module when I was doing a visual inspection.

If the module is receiving input then you just need to verify its commanding it and then if so verify the command is making it to the actuator when it doesn't work. If it has good inputs but no out put then its a bad module. If it has good output when lock operation is not working then its either wiring or actuator.

I just had a 2004 yukon here with the same issue, installed new pdm, programmed, no luck, got new key fob programmed that to vehicle, now both fobs lock and unlock, installed old pdm and they both still work. HMM not sure how that happened.