Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Monitor GDS Data
- Connect GDS to Data Link Connector (DLC).
- IG "ON"
- Press a brake-pedal.
- Check the service data related to "Brake Switch" on the GDS.
Specification: The brake switches signal changes from OFF to ON.
- Does the service data change normally?
YES
Fault is intermittent caused by poor connection in the brake light switch and/or HECU's connector or was repaired and HECU memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
Go to "TERMINAL AND CONNECTOR INSPECTION " procedure.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.