You have to remove the spoiler to get to those LED's. Too complicated for the average Joe to do, so the Owner's Handbook doesn't include instructions. Here is the section off the shop manual. Have you checked the fuses yet?

Exterior Trim and Ornamentation - Rear Spoiler

Removal and Installation
Removal

CAUTION: Always protect paintwork and glass when removing exterior components.

Disconnect the battery ground cable. For additional information, refer to: Specifications (414-00 Battery and Charging System - General Information, Specifications).

Open the liftgate glass. Remove the 2 Torx bolts. Close the liftgate glass.

Open the liftgate. Remove the 3 nuts. Close the liftgate.

Remove the rear spoiler. Disconnect the electrical connector. Disconnect the washer jet hose.

See post below for stoplight removal and installation

Spoiler Installation

Install the high mounted stoplamp. Install the Torx screws.

Install the washer jet.

Install the 2 clips.

Install the spoiler. Connect and secure the electrical connector. Connect the washer jet hose. Tighten the nuts to 10 Nm (7 lb.ft). Tighten the Torx bolts to 25 Nm (18 lb.ft).

Connect the battery ground cable. For additional information, refer to: Specifications (414-00 Battery and Charging System - General Information, Specifications).

 

Remove the stoplamp on the spoiler to access the LEDs:

Exterior Lighting - High Mounted Stoplamp

Removal and Installation
Removal

CAUTION: Always protect paintwork and glass when removing exterior components.

Disconnect the battery ground cable. For additional information, refer to: Specifications (414-00 Battery and Charging System - General Information, Specifications).

Remove the rear spoiler. For additional information, refer to: Rear Spoiler (501-08 Exterior Trim and Ornamentation, Removal and Installation).

Remove the high mounted stoplamp. Remove the 4 Torx screws.

Installation

Install the high mounted stoplamp. Install the Torx screws.

Install the spoiler. For additional information, refer to: Rear Spoiler (501-08 Exterior Trim and Ornamentation, Removal and Installation).

Connect the battery ground cable. For additional information, refer to: Specifications (414-00 Battery and Charging System - General Information, Specifications).

 

I looked in the manual but didn't see what fuse it is??

 

I didn't think there'd be a separate one for the high stop lamp, but didn't have the manual handy... Chances are it's fused with the rest of the stop lights, so if those work it's likely to be a bad LED strip up there in the spoiler.

 

How to remove rear spoiler on RRS