This automotive maintenance tutorial was specifically written to assist owners of the second generation (2017, 2018, 2019, 2020, 2021 and 2022) Mazda CX-5 SUV in changing a burnt out cargo area (or “trunk”) light bulb located in the housing attached to the plastic interior panel of the tailgate door.
Owners of other Mazda vehicles such as the CX-3, CX-30, CX-7, CX-9, Mazda3, Mazda6, MX-30, MX-5 Miata, Mazda2, CX-4, CX-8 and BT-50 may also find these DIY instructions to be helpful.
The compatible replacement “festoon” style light bulb part number is DE3175 which is available from various manufacturers such as Sylvania, GE, Bosch, PIAA and Eiko.
If you’d like to have a brighter cargo area light that will also last much longer before burning out like the traditional incandescent bulb, install a DE3175 LED unit.
The only tool needed to access and replace the bulb is a flat head screwdriver or a plastic pry bar tool.
Open the tailgate door and locate the light housing on the right (driver) side of the plastic interior panel.
Insert the blade of the screwdriver into the small notch on the left (passenger) side of the translucent plastic lens cover.
Gently pry out the lens cover.
Try to avoid using excessive force.
The lens cover should pop out relatively easily.
If the old light bulb was recently turned on, it might still be hot enough to burn your fingers. Be careful when you remove it.
Carefully pull the old light bulb out of the socket.
Try to avoid bending or damaging the metal electrical contacts.
The OEM (original equipment manufacturer) light bulb in this 2019 CX-5 was marked as part number KHA12V8W 49A16F.
Push a new number DE3175 festoon style light bulb into the socket.
Make sure the new bulb is securely held in place by the two electrical contacts.
If you’d like to have a much brighter cargo area light, install a compatible replacement DE3175 LED unit.
I recommend testing the new light bulb before you replace the lens cover.
Move the “On / Off” rocker switch to the “On” position.
Tip – If you installed an LED bulb and it doesn’t work, try removing it from the socket, rotate it 180 degrees and then push it back into the socket. Some LED bulbs are “polarized” and will only work when the “+” positive and “-” negative electrical contacts are in the correct orientation.
Line up the lens cover with the light housing.
Gently push on the cover to secure the retaining clips.
You should feel or hear the lens cover “click” or “pop” securely into place.
Be sure to write down the bulb change in your SUV’s service records.
Please check out all of my 2017-2022 Mazda CX-5 DIY Repair & Maintenance Guides.
