X4XZ LED Tail Light Bulb Unit for Cadillac ATS/XTS 2013–2018 3.6L — OE 13579168, Waterproof Aluminium

X4XZ 13579168 LED tail light bulb unit replaces OE 84198978 to restore brake-light visibility on 2013–2018 Cadillac ATS and XTS 3.6L models.

This LED tail light bulb unit is a direct-fit replacement engineered to match the electrical and mounting characteristics of late-model Cadillac ATS and XTS vehicles with the 3.6L engine. Built from corrosion-resistant aluminum and sealed against moisture, it provides bright, dependable rear illumination for braking and visibility. The unit ships individually and includes factory-style connections for a straightforward swap with no special tools required.

Will this LED tail light bulb unit fit my Cadillac ATS or XTS?

Yes—this part is designed specifically for 2013 through 2018 Cadillac ATS and XTS models equipped with the 3.6L engine. Before ordering, verify your vehicle’s tail light bulb part number and compare it to the listing images to ensure correct fitment.

• Compatible years: 2013–2018 Cadillac ATS 3.6L and XTS 3.6L
• Manufacturer reference: OE# 13579168 (replacement for OE# 84198978)
• Single-unit package: LED tail light bulb unit x1
• Check product images for connector orientation and mounting details

How bright and durable is the X4XZ LED tail light compared with the factory bulb?

The LED array yields a crisp, consistent brake signal that enhances visibility to drivers behind you. The housing is machined from high-grade aluminum and sealed against water and snow, so it resists corrosion and maintains electrical integrity under typical road conditions.

• High-quality aluminum body for heat dissipation and longevity
• Waterproof construction to protect internal wiring from moisture
• Tested to meet OEM-level performance and durability expectations

How easy is installation and what comes in the box?

Installation follows the same steps as a factory tail bulb swap and requires no special tools. The unit arrives preassembled with the correct connector and mounting points so it plugs into the stock harness and secures in the original location.

• Included: one LED tail light bulb unit (no separate instructions)
• Direct-fit design for straightforward installation
• No wiring modifications expected when used on compatible vehicles

What kind of support and warranty does X4XZ provide?

X4XZ backs the part with a one-year product service window and customer support to address fitment or quality questions. If you run into installation issues or suspect a defect, contact customer service for troubleshooting and replacement options.

• 24-hour customer service availability for inquiries
• 1-year product service coverage for defects
• Support includes installation help and return guidance

Who is this for: The X4XZ 13579168 LED tail light bulb unit is intended for Cadillac owners who need a factory-compatible, long-lasting replacement for a failed or dim tail/brake bulb on 2013–2018 ATS and XTS vehicles with the 3.6L engine. It’s a good choice for DIY installers who prefer a direct-fit, weatherproof LED upgrade that matches OEM electrical specifications and comes with manufacturer support.