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2009-2012 Lincoln MKS Lower Grille: Don't Make the Adaptive Cruise Control Mistake

This guide covers the critical differences in the lower driver-side grille for Lincoln MKS models and how to choose the right used part for your vehicle.

5 minutes to read 2009-2012 Lincoln MKS
Difficulty
3/5
Est. Time
2 hrs
DIY Doable?
✅ Yes
Shop Labor
$150 - $300
Used OEM Price
$50 - $100
⚠️ Drivable, but... — Yes, but if the grille is broken into sharp pieces or is loose enough to fall off, it can become a road hazard and should be removed or replaced.
Key Takeaways
  • The most critical factor is verifying if your MKS has Adaptive Cruise Control (ACC), as it requires a different driver-side lower grille (part # 8A5Z-17K945-CB).
  • When buying a used grille, the condition of the rear mounting tabs is more important than minor cosmetic scuffs; broken tabs will prevent a secure fit.
  • Replacement is not a simple pop-in job; the entire front bumper cover must be removed to access the grille clips from behind.
  • A used OEM grille is often a better choice than a new aftermarket one due to superior fitment, as long as it is inspected carefully for damage.
The bumper cover grille is a plastic insert located in the lower opening of the front bumper cover. On the 2009-2012 Lincoln MKS, there are three lower grilles: one on the driver's side, one in the center, and one on the passenger's side. This specific part is for the driver's side. Its primary function is aesthetic, filling the bumper opening for a finished look. It also provides a barrier that protects the components behind it—like the radiator, condenser, and various sensors—from large road debris. For some MKS models, this specific grille section also houses the adaptive cruise control radar sensor.

Symptoms of a Damaged Bumper Cover Grille

Failure of a bumper cover grille is always due to physical damage, not mechanical or electrical breakdown. Symptoms are purely visual and easy to spot.

  • Cracks or Holes: The most common symptom is visible cracking or a hole punched through the plastic mesh, usually from an impact with road debris or a minor parking collision.
  • Missing Pieces: After an impact, entire sections of the grille may break off and go missing, leaving a large, unsightly gap in the bumper.
  • Broken Mounting Tabs: The grille is held in place by a series of plastic tabs on the back. If these tabs break, the grille can become loose, rattle, or even fall out completely. You may notice it sagging or not sitting flush with the bumper cover.
  • Fading or Discoloration: Over time, the black plastic can fade to a dull gray due to sun and UV exposure, making the front of the car look aged.

Warning: A loose or broken grille can detach from the vehicle at speed, creating a hazard for other drivers. If your grille is not secure, it should be removed or replaced promptly.


The Critical Adaptive Cruise Control (ACC) Difference

Before buying a replacement grille for your 2009-2012 MKS, you must determine if your vehicle has the optional Adaptive Cruise Control (ACC) system. The radar sensor for this system is located behind the driver's side lower grille.

  • Vehicles WITHOUT ACC: These models use a standard, fully-meshed grille. The correct part number for this version is 8A5Z-17K945-AB.
  • Vehicles WITH ACC: These models require a special grille with a solid, blocked-off section designed to house the distance sensor. The part number for this version is 8A5Z-17K945-CB.

Installing the wrong grille will either leave the ACC sensor exposed and improperly mounted or block the sensor on a vehicle that has it, rendering the system inoperable. Always visually inspect your existing grille or the area behind it to confirm which version you need.


Buying a Used 2009-2012 MKS Lower Grille: What to Check

A used OEM grille is often a great value compared to a new part, but a thorough inspection is key. Here’s what to look for:

  1. Check All Mounting Tabs: This is the most important check. Flip the grille over and inspect every single mounting tab and clip. Even one broken tab can cause a poor fit or rattling. Compare it to photos of a new part to ensure all tabs are present and intact.
  2. Look for Cracks: Carefully inspect the entire grille, especially around the edges and mounting points, for any hairline cracks. A small crack can grow over time from vibration and temperature changes.
  3. Verify ACC Compatibility: Double-check whether it is the solid version for ACC models or the mesh version for non-ACC models. Do not trust a listing's title alone; look at the photos.
  4. Inspect for Previous Repairs: Look for signs of plastic welding (wavy, melted plastic on the back) or glue/epoxy. While a good repair can hold, it's a weak point and the part should be priced significantly lower.
  5. Assess the Finish: Check for deep scuffs, road rash from curb impacts, or significant fading. While some fading is normal for a used part, deep scratches cannot be easily fixed.

Pro Tip: Choosing a used OEM grille over a cheap aftermarket one often ensures a better fit. OEM parts are made from the original molds, so they clip into the bumper cover precisely as intended, avoiding the fitment issues common with some aftermarket brands.


Replacement Difficulty and Cost

Replacing the lower driver-side grille requires removing the entire front bumper cover. This involves removing numerous screws and clips in the wheel wells, under the front edge of the bumper, and under the hood. Once the bumper is off, the old grille can be unclipped from the back and the new one snapped into place. While not mechanically complex, the process is labor-intensive and requires care to avoid scratching the bumper's paint.

  • DIY Difficulty: 3 out of 5
  • Estimated Time: 1.5 - 2.5 hours
  • Tools Needed: Socket set (5.5mm, 8mm, 10mm), screwdrivers, trim removal tools.

Cost Comparison

Part TypeEstimated Cost
New OEM (without ACC)$115 - $175
New OEM (with ACC)$180 - $265
New Aftermarket$40 - $80
Used OEM$50 - $100
Shop Labor$150 - $300

Known Issues, Recalls, and TSBs

There are no recalls, technical service bulletins (TSBs), or known factory defects specifically for the bumper cover grilles on the 2009-2012 Lincoln MKS. All failures are related to external impacts or environmental exposure.

The vehicle itself has been subject to several recalls for other components, including airbags, fuel system components, and power steering issues. Owners can check for open recalls on their specific vehicle by entering their VIN on the NHTSA website.


OEM Part Numbers

Part DescriptionPart Number
Lower Grille, Driver Side (Without ACC)8A5Z-17K945-AB (replaces 8a5z17k945ba)
Lower Grille, Driver Side (With ACC)8A5Z-17K945-CB (replaces 8a5z17k945ca)
Complete Lower Grille Assembly (Without ACC)8A5Z-17K945-BB

Frequently Asked Questions (FAQ)

Can I install a grille for a non-ACC car on my car that has it?

No, the standard grille does not have the correct mounting points or solid face required for the adaptive cruise control sensor. It will leave the sensor unsecured and may cause system errors.

Do I have to remove the whole bumper to replace this small grille?

Yes, unfortunately, the grille is secured by clips from the back side of the bumper cover. Accessing these clips is not possible without removing the entire bumper cover assembly from the vehicle.

Is the driver's side grille the same as the passenger's side?

No, they are mirror images of each other and are not interchangeable. The passenger side has a different part number (8A5Z-17K946-AB).

Will a grille from a 2013 MKS fit my 2011 MKS?

No, the Lincoln MKS received a facelift for the 2013 model year with a different front bumper and grille design. You must use a part specified for the 2009-2012 model years.

Technical Specifications

OEM Part Numbers: 8A5Z-17K945-AB 8A5Z-17K945-BB 8A5Z-17K945-CB 8a5z17k945ba 8a5z17k945ca

Material: Automotive-grade plastic. Finish: Textured black (standard).

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Aug 2, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Bumper Cover Grille for:
  • Lincoln MKS: 2009201020112012
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