LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Kia >> 2019 >> K900 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Idle Stop & Go (ISG) System >> Brake Switch >> Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Brake Switch: Troubleshooting

  1. Part diagnosis
    Items Cause Symptom  
    Switch fuse Faulty fuse connection, Damaged fuse
    • DTC Code: P0504
    • Symptom: Shifting gear trouble, Starting failure, Cruise control function cancellation trouble, EPB function cancellation trouble, Stop lamp lighting trouble, ESC OFF light illuminated.
    (1) A waveform inspection is performed using an oscilloscope on each part during vehicle acceleration/braking. (Refer to stop lamp switch circuit INSPECTION PROCEDURES )
    (2) Refer to the relevant repair procedures of the part when something abnormal is discovered in the waveform (Refer to the repair procedures of the relevant part and if necessary replace it)
    Relay fuse Faulty fuse connection, Damaged fuse
    • DTC Code: P0504
    • Symptom: Shifting gear trouble, Starting failure, Cruise control function cancellation trouble, EPB function cancellation trouble, Stop lamp lighting trouble, ESC OFF light illuminated.
    Stop lamp switch
    • Damaged wiring of each part
    • Faulty connection to connector
    • Each part is defective
    • DTC Code: P0504
    • Symptom: Shifting gear trouble, Starting failure, Cruise control function cancellation trouble, EPB function cancellation trouble, Stop lamp lighting trouble, ESC OFF light illuminated.
    Stop signal electronic module (If it applies)
    • DTC Code: P0504, C2130, C2131
    • Symptom: Shifting gear trouble, Starting failure, Cruise control function cancellation trouble, EPB function cancellation trouble, Stop lamp lighting trouble, ESC OFF light illuminated.
    Engine control module (ECM)
    • DTC Code: P0504
    • Symptom: Shifting gear trouble, Cruise control function cancellation trouble
    Body control module (BCM)
    • Shifting gear trouble
    Shift-lock solenoid
    • Shifting gear trouble
    Inhibitor switch
    • Symptom: Shifting gear trouble, Starting failure, Cruise control function cancellation trouble, EPB function cancellation trouble
    Smart Key Unit (SMK)
    • Starting failure
    Electronic parking brake
    • Symptom: EPB function cancellation trouble, ESC OFF light illuminated.
    ABS/ESC control module
    (Pressure sensor)
    • Symptom: ESC OFF light illuminated.
  2. Symptom diagnosis
    Symptom Part that could be the cause  
    Trouble starting Switch fuse, Relay fuse, Stop lamp switch, Stop signal electronic module, ABS/ESC control module, Each wire, Connector (1) Inspect waveform using an oscilloscope on each part during vehicle acceleration/braking. (Refer to stop lamp switch circuit INSPECTION PROCEDURES .)
    (2) Refer to the relevant repair procedures of the part when something abnormal is discovered in the waveform (Refer to the repair procedures of the relevant part and if necessary replace it)
    Trouble shifting gears Switch fuse, Relay fuse, Stop lamp switch, Stop signal electronic module, BCM, ECM, Inhibitor switch, Each wire, Connector
    ESC OFF light illuminated Switch fuse, Relay fuse, Stop lamp switch, Stop signal electronic module, ABS/ESC control module, Each wire, Connector
    P0504 Switch fuse, Relay fuse, Stop lamp switch, Stop signal electronic module, ECM, Each wire, Connector
    Stop lamp not working Switch fuse, Relay fuse, Stop lamp switch, Stop signal electronic module, Wire/Connector disconnected
    Stop lamp always turned on Stop lamp switch, Stop signal electronic module, Wiring short circuit, Damaged fuse
  3. Stop lamp switch system diagnosis
    G13143490Courtesy of KIA MOTORS AMERICA, INC.
    G13143491Courtesy of KIA MOTORS AMERICA, INC.

    SSEM: Stop Signal Electronic Module

  4. Refer to DTC INDEX when the related DTC codes are displayed.