2002 Suburban Power Locks Not Working
 

Bought a 2002 suburban 1500 lt 4x4 about 6 months ago and it has been great. Unfortunately, about a week ago we were out running errands and the power locks just stopped working. They no longer lock/unlock automatically when you start driving or place the vehicle in park. We have 2 FOB's that I just programmed about 2 weeks ago. So far I have replaced all fuses/relays in the fuse box and under the hood. I removed the drivers side switch module and cleaned everything I could but I wasn't sure how to test that switch. I have also tried to look around for any loose or pinched wires but I haven't seen anything.

Other symptoms: noticed that I only hear the relay click when I press unlock from any switch (drivers side, passenger, lift gate, or FOB) but I don't hear anything when I press lock from any switch. Also, I played around with the relays in the fuse box and noticed that when I remove the drivers side lock the unlock button will partially work. I also noticed that the relay for the drivers side lock is warm to the touch, while none of the others are warm at all. Could that be a problem?

Any suggestions?

Thanks!

Welcome to the forum. Since your first problem started noticing your statement,

They no longer lock/unlock automatically when you start driving or place the vehicle in park.

I believe I would look for some type of switch located on the steering column, since the gear shifting controls locking/unlocking the locks. JMHO and good luck.
David g.

The warm relay sounds suspicious, try swapping it with the drivers door UNLOCK relay. If the symptoms change the relay may be stuck closed. If the symptoms remain the same something may be energizing a relay all the time. You should NOT hear the relay clicking when you remove/replace it. The relays do get energized by the BCM, a reset(disconnect the battery) may help. A sticking door LOCK/UNLOCK button may be another possibility.
All the relays have to be plugged in for locks to work properly.