2004 Tahoe Security Glitch

[dps01]

the FOB still only works on the lock button. the unlock button does nothing.

If you have not tried cleaning the fob yet, try cleaning with DeoxIT D5. It’s pricey for a small can, but works wonders on old switches / contact's.

 

[Doubeleive]

UPDATE!

The new master switch looks great, no more faded black.
It solved the unlock/lock issue within the car, but the FOB still only works on the lock button. the unlock button does nothing.
I will give it another try with buying a new FOB (i only have one) but I'm not optimistic.
Any suggestions with diving deeper into the ECU or harness?
I do have HP Tuners by the way.

fob issue's are usually just the fob, you can try opening the fob up and clean the pcb board with rubbing alcohol dabbed on a soft cloth (rub the cloth on the button contacts) and then put it back together and see if it works better or not.
the fob is pretty basic, upper and bottom plastic piece, board, battery, rubber pad