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DTC P0703: Malfunction of Stoplight Switch

 
 
 
 
DIAGNOSTIC FUNCTION
TCM detects malfunction using the stoplight switch signal sent from the ETACS-ECU.
 
 
DESCRIPTIONS OF MONITOR METHODS
Drive the vehicle at 30 km/h (19 mph) or more for 10 seconds, and then turn the ignition switch to the "LOCK" (OFF) position. In this sequential operation, no variation has been found in the stoplight switch input signal in two consecutive times.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Vehicle speed: 30 km/h (19 mph) or more.
  • Voltage of battery: 10 volts or more.
Judgment Criteria
  • The change of stoplight switch signal during driving cycle: no occurrence (10 seconds × 2 times).
 
 
OBD-II DRIVE CYCLE PATTERN
Drive the vehicle for 10 seconds or more at 30 km/h (19 mph) or higher (2 drive cycle)
 
 
PROBABLE CAUSES
  • Malfunction of CAN bus line
  • Malfunction of the stoplight switch
  • Damaged wiring harness and connectors
  • Malfunction of TCM
  • Malfunction of ETACS-ECU
 
 
DIAGNOSIS
STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis, CAN Bus Diagnostics Table ).
 
STEP 2. M.U.T.-III data list
Item 59: Brake switch
OK: The service data changes in response to the brake operation.
Is the check result normal?
Go to Step 3.
Check the stoplight switch circuit (Refer to GROUP 54A - ETACS, Symptom Chart, Input Signal Chart ).
 
STEP 3. Symptom recheck after erasing diagnostic trouble code
Is the diagnostic trouble code set?
Replace TCM.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).