1. Wiring aged or corroded causing poor contact on the socket.
2. Wiring open circuit, short circuit causing bulb could not function.
3. Brake switch faulty or wiring problem, causing it unable to provide braking signal which lead to brake lamp not functioning because the ECU wrongly recognize that the brake pedal is not press.
Suggest to repair at workshop as soon as possible.
1. Check if there is check light or error message in the meter cluster, identify the malfunction item.
2. Take out the brake lamp bulb and check if it is broken.
3. Use the multimeter to check if the wiring harness has any abnormality, break, short circuit, corroded or poor connection.
4. Check if the brake lamp on off switch is broken or the signal is transmitting normally.
5. Based on the inspection outcome, replace the bulb, wiring harness or the on off switch.
5. If the issue is the wiring and wiring aged is not severe, can repair with soldering to save cost.