It is possible that the light itself is bad ..... you can unplug the light and use a test probe and see if it is getting power , or you can run a jumper wire (with it unplugged) and connect it to the brake light that you know works , then turn it on , it should light up , if not then the light itself is the issue , I don't know on that model if it is a light bulb or a LED , but either way , those tests should give you a answer , if you are not getting power to the bulb , the test probe will help trace it to where the power stops (the clamp goes to a good ground and you poke the probe into the wire itself or touch the connector) , if you are getting power the probe will light ....
Test Probe
