Stop Lamp Switch

TROUBLESHOOTING

1. 1
   Diagnostic Procedure

   Item	Cause	Symptom
   Fuse Switch	Loose fuse connection, damaged fuse	DTC: P0504 Symptom: Gear shifting difficult, start failure, cruise control cancel function difficult, EPB release function difficult, brake lights difficult to turn on, ESP OFF indicator light on	① Check the signal waveform with an oscilloscope on each component while accelerating/decelerating the vehicle. (Refer to Brake Light Switch Circuit Inspection Procedures.) ② If anything abnormal is found in the signal, refer to the proper repair procedure for the component (refer to the repair and replacement procedure of the relevant component if necessary).
   Fuse Relay	Loose fuse connection, damaged fuse	DTC: P0504 Symptom: Gear shifting difficult, start failure, cruise control cancel function difficult, EPB release function difficult, brake lights difficult to turn on, ESP OFF indicator light on.
   Stop Lamp Switch	Damaged wiring of each component Incorrect connector connection Each component is faulty	DTC: P0504 Symptom: Gear shifting difficult, start failure, cruise control cancel function difficult, EPB release function difficult, brake lights difficult to turn on, ESP OFF indicator light on.
   Brake light electronic module Shutdown (if equipped)		Diagnostic Trouble Codes: P0504, C2130, C2131 Symptom: Gear shifting difficult, start failure, cruise control cancel function difficult, EPB release function difficult, brake lights difficult to turn on, ESP OFF indicator light on.
   Engine Control Module (ECM)		DTC: P0504 Symptom: Shift error, cruise control cancel error
   Body Control Module (BCM)		Shift failure
   Lock solenoid		Shift failure
   SHIFT LOCK SWITCH		Symptom: Gear shifting difficult, start failure, cruise control cancel function difficult, EPB release function difficult
   Smart Key Unit (SMK)		Start failure
   Electronic Parking Brake (EPB)		Symptom: EPB lock failure, ESP OFF indicator light on
   ABS/VDC control unit [Pressure sensor]		Symptom: ESP OFF indicator light on.

2. 2
   Symptom Diagnostic Procedure

   Symptom	Possible Causes
   Start failure	Switch fuse, relay fuse, brake light switch, brake light electronic module, ABS/VDC control module, each wire, connector	① Check the signal waveform with an oscilloscope on each component while accelerating/decelerating the vehicle. (Refer to Brake Light Switch Circuit Inspection Procedures.) ② If anything abnormal is found in the signal, refer to the proper repair procedure for the component (refer to the repair and replacement procedure of the relevant component if necessary).
   Faulty shift switches	Switch fuse, relay fuse, brake light switch, brake light electronic module, BCM, ECM, shift lock switch, each wire, connector
   ESP OFF indicator light on	Switch fuse, relay fuse, brake light switch, brake light electronic module, ABS/VDC control module, each wire, connector
   P0504	Switch fuse, relay fuse, brake light switch, brake light electronic module, ECM, each wire, connector
   Stop lamp does not work	Switch fuse, relay fuse, brake light switch, brake light electronic module, wire/connector disconnected
   Brake lights always on	Brake light switch, brake light electronic module, wiring short circuit, blown fuse

3. 3
   Stop Lamp Switch System Diagnosis

   

   

   SSEM: Stop Lamp Electronic Module
4. 4
   Refer to the DTC troubleshooting guide when the relevant DTCs are displayed.