Hyundai Sonata LF Quiz
Brake System

Stop Lamp Switch

In this manual: Brake System
General Information — 9Engine Mechanical System — 90Engine Electrical System — 58Emission Control System — 24Engine Control System/Fuel System — 114Drive Shaft and Axle — 15Suspension System — 35Steering — 19Restraints — 50Brake System — 54Body (Interior and Exterior) — 213Body Electrical System — 241Heating, Ventilation, and Air Conditioning — 56DCT (Dual Clutch Transmission) System — 52
4steps
~24min
2/5difficulty
Done 0 of 4

Troubleshooting

  1. Component Inspection
    Items Cause Symptom
    Fuse Switch Loose fuse connection, blown fuse
    • DTC: P0504
    • Symptom: Shift problems, starting failure, cruise control cancel function problem, EPB cancel function problem, stop lamp malfunction, ESP OFF lamp illuminated.
    		 Check the waveform with an oscilloscope on each component during acceleration/braking. (Refer to the stop lamp switch circuit inspection procedure.)

    Refer to the appropriate component repair procedures when an abnormal waveform is detected (refer to the repair procedures for the applicable component and replace it if necessary).
    Fuse Relay Loose fuse connection, blown fuse
    • DTC: P0504
    • Symptom: Shift problems, starting failure, cruise control cancel function problem, EPB cancel function problem, stop lamp malfunction, ESP OFF lamp illuminated.
    Stop Lamp Switch
    • Damaged wiring of each component
    • Incorrect connector connection
    • Faulty component
    • DTC: P0504
    • Symptom: Shift problems, starting failure, cruise control cancel function problem, EPB cancel function problem, stop lamp malfunction, ESP OFF lamp illuminated.
    Stop Lamp Electronic
    Module (if applicable)
    • DTC: P0504, C2130, C2131
    • Symptom: Shift problems, starting failure, cruise control cancel function problem, EPB cancel function problem, stop lamp malfunction, ESP OFF lamp illuminated.
    Engine Control Module (ECM)
    • DTC: P0504
    • Symptom: Shift problems, cruise control cancel problem.
    Body Control Module (BCM)
    • Gear Shifting Concerns
    Shift Lock Solenoid
    • Gear Shifting Concerns
    Inhibitor Switch
    • Symptom: Shift problems, starting failure, cruise control cancel function problem, EPB cancel function problem
    Smart Key Unit (SMK)
    • Starting Failure
    Electronic Parking Brake (EPB)
    • Symptom: EPB cancel function problem, ESP OFF lamp illuminated.
    ABS/VDC Control Unit (Pressure Sensor)
    • Symptom: ESP OFF lamp illuminated.
  2. Symptom Diagnostics
    Symptom Possible Cause
    Starting Problems Switch Fuse, Relay Fuse, Stop Lamp Switch, Stop Lamp Electronic Module, ABS/VDC Control Module, Each Wire, Connector Check the waveform using an oscilloscope on each part while accelerating/braking the vehicle. (Refer to Stop Lamp Switch Circuit Inspection Procedure)

    Refer to the applicable part repair procedures when an abnormality is detected in the waveform (refer to the repair procedures for the applicable part and replace it if necessary).
    Gear Shifting Concerns Switch Fuse, Relay Fuse, Stop Lamp Switch, Stop Lamp Electronic Module, BCM, ECM, Inhibitor Switch, Each Wire, Connector
    ESP OFF indicator light is on Switch Fuse, Relay Fuse, Stop Lamp Switch, Stop Lamp Electronic Module, ABS/VDC Control Module, Each Wire, Connector
    P0504 Switch Fuse, Relay Fuse, Stop Lamp Switch, Stop Lamp Electronic Module, ECM, Each Wire, Connector
    Stop lamp does not work Switch fuse, relay fuse, stop lamp switch, stop lamp electronic module, disconnected wire/connector
    Stop lamp is always
    on    		 Stop lamp switch, stop lamp electronic module,
    Wiring short circuit, blown fuse
  3. Stop Lamp Switch System Diagnosis
    SSEM: Stop Lamp Electronic Module
  4. Refer to the DTC Chart when the applicable DTCs are displayed.

Test yourself

A quick Hyundai Sonata LF quiz: every answer comes with an explanation and a link to the manual page.