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DTC B1136 Stoplight switch
 
 
cautionWhen replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
When the stoplight switch status is different from the brake switch information received from ETACS-ECU via CAN, KOS&OSS-ECU sets DTC B1136, and displays the power supply system error warning the combination meter.
 
 
JUDGMENT CRITERIA
Check Conditions
  • After KOS&OSS-ECU activation
Judgment Criterion
  • The difference between the stoplight switch condition and the stoplight switch information has been detected.
  • The stoplight switch information from the ETACS-ECU cannot be received via CAN communication.
 
 
PROBABLE CAUSES
  • CAN bus line malfunction
  • Damaged wiring harness or connector (short to ground or open circuit between stoplight switch and KOS&OSS-ECU or between stoplight switch and ETACS-ECU)
  • ETACS-ECU malfunction
  • Malfunction of KOS&OSS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line
After performing the forced power supply output (Refer to ) "IG ON" using the scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Diagnosis ).
 
STEP 2. Check of short to ground or open circuit in STP1 line between stoplight switch connector and KOS&OSS-ECU connector
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check of short to ground or open circuit in BKLP line between stoplight switch connector and ETACS-ECU connector
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check the other system data list
Check the ETACS-ECU data list.
  • Item No.113: Stoplight switch (Refer to GROUP 54A - ETACS, Service Data Reference Table ).
Is the check result normal?
Go to Step 5.
Diagnose the ETACS-ECU (Refer to GROUP 54A - ETACS - Trouble Symptom Chart for Input Signal ).
 
STEP 5. Using scan tool (M.U.T.-IIISE), check the data list
Check the KOS&OSS-ECU data list.
  • Operate the brake pedal.
 
Item No.Check itemOperation stateDisplay
5Stop light switchBrake pedal is depressedON
Brake pedal releasedOFF
OK: Operation state and data list display agree with each other.
Is the check result normal?
Go to Step 6.
Replace the KOS&OSS-ECU and register the ID codes (Refer to ).
 
STEP 6. Check whether the DTC is set again.
Is the DTC set?
Replace the KOS&OSS-ECU and register the ID codes (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).