Hyundai Sonata LF Quiz
Brake System

Stop Lamp Switch Repair Procedures

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
19steps
~114min
4/5difficulty
Done 0 of 19

Adjustment

  1. Turn the ignition switch OFF and disconnect the negative (-) battery cable.
  2. Remove the lower under cover. (Refer to Body - Under Cover)
  3. Remove the knee airbag. (Refer to Restraint - "Airbag Module")
  4. Check the clearance between the stop lamp switch and the bracket.

    Stop lamp switch clearance: 1.0-2.0 mm (0.04-0.08 in.)

  5. If the clearance between the stop lamp switch and the bracket is not 1.0 - 2.0 mm (0.04 - 0.08 in.), check the mounting clip and other parts around the stop lamp switch.
  6. If everything is normal, remove the stop lamp switch and install it again.

Inspection

1. Check Fuses. Install a test fuse on the switch fuse and relay fuse part to check for normal connection.
2. GDS Data Analysis
  1. Analyze the GDS data and confirm that there is a problem with the stop lamp switch.
    1. Connect the GDS to the self-diagnosis connector.
    2. Turn the ignition switch ON.
    3. Press the brake pedal.
    4. Check the 'Brake Switch' item in the GDS 'Sensor Data'. Normal waveform: The signal value will change according to the brake switch ON/OFF state.
3. Inspect Connector of Each Part. Check whether each connector is damaged, whether terminals are overheated or incompletely connected. [Engine Room Junction Box]
[Stop Lamp Electronic Module]
[ABS/VDC Control Module]
4. Inspect the stop lamp circuit. Connect the probe to each terminal wire and check the oscilloscope waveform. [Stop Lamp Switch Input/Output]
[Brake light electronic module input/output]
[Oscilloscope Waveform Screen]

Removal

  1. Turn the ignition switch OFF and disconnect the negative (-) battery cable.
  2. Remove the lower under cover. (Refer to Body - Under Cover)
  3. Remove the knee airbag. (Refer to Restraint - "Airbag Module")
  4. Disconnect the stop lamp switch connector (A).
  5. Pull the lock plate (A) as shown by the arrow.
  6. Turn the stop lamp switch 45° counterclockwise and remove it.
  7. Inspect the removed stop lamp switch according to the procedures described below.
    1. Confirm normal connection with the terminal part.
      A. Check whether the connector is securely connected and whether the connection mark is present.
    2. Perform resistance inspection of the part.
      Resistance (Ω) 3-4 1-2
      Plunger not protruding
      (switch OFF)      		 Infinity 0
      Plunger protruding
      (switch ON)      		 0 Infinity

Installation

  1. Hold the brake pedal arm and fully insert the stop lamp switch, concealing the contact part.
  2. After installation, turn the lock switch (A) 45° clockwise, then assemble the lock plate (B) by pressing it.
  3. Check the clearance between the stop lamp switch and the bracket.

    Stop lamp switch clearance: 1.0-2.0 mm (0.04-0.08 in.)

  4. Connect the stop lamp switch connector.
  5. Install the knee airbag. (Refer to Restraint System - Knee Airbag Module (KAB))
  6. Install the lower under cover. (Refer to Body - Under Cover)

Test yourself

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