My power locks for both front doors stopped working at the same time. Can't open them with the key fob, the button on the outside of the handle, or any of the interior buttons. I can manually lock them physically. The rear doors/trunk work completely fine. The front door locks don't move at all when the button is pressed, and there is no humming/clicking sound coming from the inside of the door panel. I've seen online that the actuators commonly go out on Infinitis, but the fact that both front doors went out at the same time and the lack of any humming sound makes me unsure. Any suggestions to diagnose this?

 

Do the rear door locks trigger with the driver side switch? Or only at each rear door switch?

The front door locks are only triggered by the driver side (master) window switch which communicates via com link with the BCM to trigger the front (L/R/all) actuator(s). The passenger (slave) switch sends a signal to the driver (master) which tells the BCM to trigger the actuator. In contrast, the rear doors communicate directly with the BCM to trigger each rear actuator.

The only kink in the chain that I can see is that the outside door "request switch" does not work as well. This could indicate a issue with the BCM. Did you check for any water leaks in/ near/ around the passenger footwell/ kickpanel area? Any other erratic electrical gremlins?

My guess would be a bad switch. Unfortunately, there is no real way to test these switches without specialized equipment.

Perhaps someone else will have other ideas. But I highly doubt both front actuators "gave up the ghost" at the same time.