How to Fix Chevrolet Tahoe Brake Light Fail - Complete Guide

By Nick Marchenko, PhD

Chevrolet Tahoe owners occasionally face issues with their brake lights either staying constantly on, failing to light up, or behaving erratically. This guide amalgamates insights and experiences from various threads to provide a comprehensive DIY approach to troubleshooting and fixing brake light problems in your Chevrolet Tahoe.

Step 1: Initial Checks

• Inspect Fuses: Check the brake light fuse under the dashboard and the stop light fuses under the hood. Replace any blown fuses. Relevant fuses include PARK LP, VEH STOP, RR PRK, LR PRK, HAZ LP (engine compartment) and TURN (driver's side block).
• Check the Light Bulbs: Start by ensuring the tail lights/brake lights bulbs are functional. Replace any blown bulbs.

If you are not sure what light bulbs are used in your Chevrolet Tahoe - check the chart below:

• 2015;
• 2014;
• 2013;
• 2012;
• 2011;
• 2010;
• 2009;
• 2008;
• 2007;

Step 2: Brake Light Switch

• Inspect and Replace Switch: Examine the brake light switch located under the brake pedal. If faulty, replace it. Note that newer Tahoe models use a switch that pulls a bracket to signal brake engagement.
• Bypass Test: For a quick test, bypass the switch by placing a jumper wire into pins (for newer models). If lights behave normally, the switch is likely at fault.

Step 3: Body Control Module (BCM) and Wiring

• BCM Check: The BCM controls brake lights. Disconnect the brown connector at the BCM with the key off. If lights go out, the issue could be with the BCM or brake switch harness leading to the BCM.
• Wiring Inspection: Inspect the wiring leading to the brake switch and tail lights. Check for frayed, loose, or damaged wires and repair or replace as necessary. Pay special attention to the wires in the plug that connects to the brake switch.

Step 4: Ground Connections and Relays

• Examine Grounds: Check the ground connections for the tail lights, typically located on the left frame rail behind the rear tire. Repair any poor connections.
• Relay Testing: Examine the PRK LAMP relay in the underhood fuse block. Replace if faulty.

Step 5: Advanced Diagnostics

• Check for Cross-Wiring: Investigate for any cross-over in the wiring harness, connectors, or bulb sockets, especially if the lights stay on when the PRK LAMP relay is removed.
• Electronics Cleaner: Use an electronics cleaner/lubricant on the BCM connectors to address potential fretting corrosion.

Step 6: Additional Considerations

• Trailer Brake Controller: If your Tahoe has a trailer brake controller, inspect it for issues. Check the trailer plug for corrosion or mud.
• Circuit Testing: Utilize a multimeter to test electrical paths, especially if brake lights behave unexpectedly with the headlight switch or appear dim.

Shop From Amazon

WeePro Vpro850L Digital Multimeter DC AC Voltmeter, Ohm Volt Amp Test Meter, Electric Test...

Klein Tools 69149P Electrical Test Kit with Digital Multimeter, Noncontact Voltage Tester...

Conclusion

Addressing brake light issues in your Chevrolet Tahoe may require a step-by-step approach, covering everything from basic checks to more complex electrical diagnostics. If after these steps the problem persists, consider consulting a professional or visit a dealership, especially for tasks like BCM programming or intricate wiring issues.

See Also:

• FuelSys1 OL-Fault in a 2007 Chevy Tahoe
• How To Replace 2016 Chevrolet Tahoe License Plate Bulb
• What Causes Chevrolet Tahoe Won’t Start & Make Clicking Noise

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.

Full profile → LinkedIn →