2002 Tahoe -- Door Locks Issue

[IcePhreak]

Hey guys, having a recent issue with my Tahoe. None of the door locks work, I can hear the relays clicking. Key fob activates the locks as well but only hear the relay clicking. When you open the door the alarm starts going off. Also the security light is illumated on the dash, goes away when it starts. I tried a hard reset of the battery but to no avail. I find it hard to believe all 6 lock actuators failed at one time.
Thanks in advance.

 

[S33k3r]

It sounds like your master lock switch may be dead. This is very similar to what I experienced in the last month or so. I heard the relays working, but the doors would never lock. Replacing the master lock switch fixed the problem for me.

 

[IcePhreak]

I'll check into that, wonder if I can just unplug it to see.

 

[IcePhreak]

Update:
Pulled the master control on drivers side and that didn't make a difference. The wife said this happened after she dropped her key fob and the alarm went off. I find that to be coincidental, I pulled the key fob battery and removed it from the vehicle, still the same issue.

 

[Jimmyy]

Do the doors unlock/lock with any of the door switches? Can you switch the relay with another one for a test?

 

[IcePhreak]

Do the doors unlock/lock with any of the door switches? Can you switch the relay with another one for a test?

None of the door lock switches unlock or lock, I've messed around with a few of the relays, all they do is click. Might but new relays and try again, but it's weird that the alarm goes off when the door is opened.

 

[IcePhreak]

Few updates,
If I take one of the door lock relays and plug it in and out it locks the doors,
Unhooked battery and right when you touch positive it locks the doors. No other functions work.

UPDATE:
Left the battery off for 12 or so hours, reconnected and everything worked fine for about 10 minutes.
Going to check all chasis grounds and retry. If they are good I'm going to replace the BCM.
Cheers.

 

[Jimmyy]

Almost acts like a switch is stuck. How are the locks programmed as far as unlock, by shifting in to park or by key removal? I would unplug the drivers door lock switch.

 

[IcePhreak]

Almost acts like a switch is stuck. How are the locks programmed as far as unlock, by shifting in to park or by key removal? I would unplug the drivers door lock switch.

When all was good they lock and unlock when put into drive and park respectively. Now when you switch to drive or park it just clicks those relays. I kinda was thinking that as well. I unplugged the drivers switch controls and that didn't make any difference.

 

[bdgvpkgxxx]

Hey guys, having a recent issue with my Tahoe. None of the door locks work, I can hear the relays clicking. Key fob activates the locks as well but only hear the relay clicking. When you open the door the alarm starts going off. Also the security light is illumated on the dash, goes away when it starts. I tried a hard reset of the battery but to no avail. I find it hard to believe all 6 lock actuators failed at one time.
Thanks in advance.

Unplug passenger lock switch check for corrosion in the plug. Or the switch panel is bad. Thought bcm until i traced back to switches it rained wife forgot windows was down changed all switch panels from junk yards and it worked.