If the high and low relays are energizing then you need to trace why in this case the Low Beams are not receiving +12 volts when the relay is active.
You need to energize the Low Beam Relay and by following the Wiring Diagrams put one lead of your voltmeter on first one side of Fuse# 4 10 A on the internal Fuse Panel (Junction Block). Use page 8W-50-3 as reference.
The other lead of the meter goes to ground/chassis.
Turn Ignition ON.
You should see +12 volts on both side of the fuse if it is not blown.
If there is no voltage there at all then you will have to remove the JB to get access to the Low Beam Relay that you hear energizing on the rear side of the JB.
There is a Component Location section in the beginning of the Wiring Diagrams Section 8W...there is a picture there of the layout of the JB so you can see which relay is the Low Beam Relay.
At this stage you can swap over the Low Beam Relay with one of the many identical ones around it and see if your problem is gone.
Then measure on the Low Beam Relay pin #30 for +12 volts with respect to ground...should be there if Ignition is ON.
All of this circuitry is on page 8W-50-3
Then check if that +12 volts is on pin# 87 when the Low Beam is energized. At this stage you should be able to feel the relay energizing (clicking) as you operate the stalk for low beam.
Pin #85 should have +12 volts with respect to ground.
Now with one meter lead on pin #85 or #30....move the other meter lead from ground over to pin #86 which gets switched to ground by the BCM when you activate the Low Beam Switch. You should see +12 volts on the meter which would prove that the Relay is getting activated by Ground on pin #86 coming from the BCM.
If the above is working then you need to trace the +12 volts out of the JB via Pin #4 on connector C3...on a White/tan wire. This leaves the page at the bottom right to the following page # 8W-50-4.
You should see this +12 volts going into the Right Headlamp socket so check if it is there. This wire goes through connector C106 pin #10 so if this +12 volts has gone missing at the headlamp while it was present at Pin #4 on connector C3 at the JB then the voltage is not going through connector C106 pin #10 ie. the connector C106 may have dirty pins.
You can find the physical position of C106 at the rear of the Component Location section at the beginning of section 8W.
The Left Headlamp socket gets the same treatment via fuse # 5 so the fact that neither left or right low beam is working would point to the Low Beam Relay being faulty or not getting +12 volts on pin#85 or Ground on pin # 86.
If you do not get ground on pin #86 with respect to +12 volts when the relay is energized..you need to follow the wiring to the BCM on page 8W-45-3.
See how far you get with the above and then we can go into the BCM if needed.
Have fun.