When I step on the brake or use turn signal, the left rear brake and turn single does not work but the driving and reverse lights work okay. Also the other side works okay. Left mirror and front lights work okay...all the lamps are checked and okay and wires look good.
I used ForScan to clear any BCM codes with no luck.
Any suggestions?

Thank

 

You said you checked the lamp and the wiring and they are good, so swapping the left to right should work. Try it. It's a 3157 bulb right?