Guide: 2nd Generation CX-9: Cargo light bulb replacement/upgrade


Work In Progress..
'18 CX-9 Signature
This is a DIY How-To for a cargo light bulb replacement/upgrade for the 2nd Generation Mazda CX-9. I decided to document this process as it seems nobody has done it yet. Hopefully this helps someone who wants to upgrade their lighting or save a trip to the dealership.

This process was documented/photographed by myself, using my crappy cellphone camera and my 2018 Mazda CX-9 Signature as the "demo" vehicle. This DIY is provided as a learning aid and reference guide. I assume no responsibility for any warranties that may be voided or damages you may inflict on yourself or your vehicle.

What you'll need:

- Flathead screwdriver (having two flatheads helps a lot)
- Replacement bulb (halogen or LED, bulb type is DE3175, and measures 31 x 12 x 12 mm)
- Thin cloth (optional, you can use this to wrap the tip of the flathead screwdriver)

1. Make sure the vehicle is off! Disconnecting the battery is not necessary, but you can if you'd like.

2. Open the liftgate. Make sure the cargo switch is turned off (the switch will protrude slightly in the OFF position).

3. If you have a thin cloth of some sort, wrap it around the flathead tip to prevent potential scratches/gouges in the liftgate. Wedge a flathead in the slot near the switch to pry the cover open a little bit. If you have a second flathead, insert it between the cover and the liftgate and work it around the edges to pop the cover off. The cover will literally pop off, so bear in mind that you may need to catch it or lay down a towel).



4. The bulb will be exposed. Remove it by pulling out the side closest to the switch first, then the other side. Again, be prepared to catch the bulb as it comes out.



5. Install the new bulb. I took this opportunity to upgrade the halogen bulb to an LED bulb. Please do your research when buying an LED bulb to ensure that you get the right bulb and that you will not encounter errors from the change in voltage. Reinstalling the bulb was a little tricky. I found it easiest to insert the bulb on the far end of the switch first, as the metal tab it sits on has some flex. Then I slowly pushed the other side in. Note that you won't hear it clip in or anything. Also note that in the pic below, you can see that the bulb isn't installed correctly on the side closest to the switch. The pointy end should be resting in the depressed area. I need to go back and fix that.



6. With the bulb replaced, flip the cargo light switch to test the bulb (if you disconnected the battery, be sure to reconnect it first).

7. Reinstall the cargo light cover. It'll just snap back on when you press on the edges.

Here are a couple of comparison photos I took. As you can see, the LED bulb is much brighter than the OEM halogen bulb. Unfortunately, this doesn't solve the issue of the single light source of the cargo area being behind you. Oh well! At least it looks nice, haha.





Also, here's an Amazon link to the bulb I used (non-affiliate link). It is a DE3175 bulb, and measures 31 x 12 x 12 mm.

Hope that helped you guys out! If you have any questions, post them here and I'll do my best to answer them.
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2016 CX-5 GT, 2017 CX-9 GT
Again, always great to have these guides on hand! Thank you for the time and effort sm1ke! :)