Mazda CX-5 Brake Lights Are Not Working - List Of DIY Solutions

By Nick Marchenko, PhD

In the spirit of ensuring safety and reliability in our vehicles, it's paramount to address even the smallest issues with diligence and care. A common concern among Mazda CX-5 owners, notably the 2021 model, revolves around brake light failures, a problem that not only compromises safety but also poses potential legal issues. This guide is crafted to empower you, the vehicle owner, with the knowledge to diagnose and fix brake light problems in your Mazda CX-5, ensuring your vehicle remains a paragon of safety on the roads.

Preliminary Checks

Before diving into troubleshooting, perform a simple visual inspection to confirm which brake lights are not functioning. In the scenario where the top brake light strip operates but the lower brake lights do not, it's an indication that the issue might not be with the brake light switch (since one of the brake lights is working) but rather with the bulbs or the connections specific to the non-functioning lights.

Step 1: Inspect the Bulbs

• Access the Brake Light Assembly: Begin by opening the trunk or hatchback of your Mazda CX-5 to access the brake light assembly. This usually involves removing a panel or cover that shields the backside of the brake lights.
• Remove and Inspect the Bulbs: Carefully remove the bulbs by twisting them counter-clockwise (in most cases) and pull them out of their sockets. Examine the bulbs for any signs of blackening, filament damage, or breakage.
• Test or Replace Bulbs: If the bulbs appear damaged, replace them with new ones of the same type and wattage. If the bulbs seem intact but you're uncertain, you can test them by swapping them with bulbs from a functioning light segment or using a multimeter to check for continuity.

Before buying a replacement bulbs, check the chart below to ensure that you are choosing the right bulbs for a brake light position of your Mazda CX-5:

• 2022;
• 2021;
• 2020;
• 2019;
• 2018;
• 2017;
• 2016;
• 2015;
• 2014;
• 2013;

Step 2: Check for Loose Connections and Corrosion

• Inspect the Socket: With the bulbs removed, inspect the socket for any signs of corrosion or damage. Corrosion can interfere with the electrical connection, preventing the bulb from lighting up.
• Clean the Contacts: If corrosion is present, gently clean the contacts with a small wire brush or sandpaper to restore a clean, metal surface. Apply a dielectric grease to protect the contacts from future corrosion.
• Ensure Tight Connections: Make sure that the bulb sockets are secure and that there are no loose wires or connections in the brake light assembly. A loose connection could be responsible for intermittent or complete failure of the brake lights.

Step 3: Investigate the Fuse Box

• Locate the Fuse Box: Consult your Mazda CX-5's owner's manual to locate the fuse box. The manual should also provide a diagram indicating which fuse corresponds to the brake lights.
• Check the Brake Light Fuse: Remove the fuse using a fuse puller and inspect it for a broken wire inside. If the fuse is blown, replace it with a new fuse of the same amperage rating.

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Additional Considerations

• Warranty Coverage: If your Mazda CX-5 is still under warranty, it's advisable to let authorized dealers address any electrical or mechanical issues, including brake light failures. This ensures that repairs are performed correctly and maintains your warranty coverage.
• Seek Professional Help if Needed: Should these steps not resolve the issue, or if you're uncomfortable performing any of these tasks, consulting a professional mechanic or taking your vehicle to a Mazda dealer is recommended. Sometimes, issues may stem from more complex electrical problems or require specialized diagnostic tools.

Conclusion

Addressing brake light failures in your Mazda CX-5 not only contributes to your safety but also to the safety of others on the road. By following these steps, you can ensure that your vehicle remains a reliable and safe mode of transportation. Remember, regular maintenance and prompt attention to any issues are key to preserving the longevity and performance of your Mazda CX-5.

See Also:

• Mazda i-Stop Warning Light Flashing Orange - What to Do?
• What does Mazda DSC malfunction mean?
• Battery Management System Malfunction - Symptoms & Causes
• Strange Mazda BSM Malfunction Issue: Causes & Fixes
• Why Mazda CX-5 ESP light is on - Causes & How to fix
• How to choose the right cargo area light bulbs?

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

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