Code No.B1136 Stop lamp switch


caution When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION



JUDGEMENT CRITERIA


Check Conditions
  • After OSS-ECU activation
Judgment Criterion
  • When the following conditions are met:

  1. When the stop lamp switch is OFF and the brake switch status is ON, 1.5 seconds or more have elapsed
  2. When the stop lamp switch is ON and the brake switch status is OFF, 1.5 seconds or more have elapsed

PROBABLE CAUSES



  • Damaged wiring harness or connector (short to earth or open circuit between stop lamp switch and OSS-ECU or between stop lamp switch and ETACS-ECU)
  • ETACS-ECU malfunction
  • Malfunction of OSS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check of short to earth and open circuit in signal line between stop lamp switch connector and OSS-ECU connector

Q. Is the check result normal?
Go to Step 2.
Repair the connector(s) or wiring harness.

STEP 2. Check of short to earth and open circuit in signal line between stop lamp switch connector and ETACS-ECU connector

Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. M.U.T.-III other system data list
Check the ETACS-ECU data list.

  • Item No.290: Stop lamp switch (Refer to GROUP 54A - ETACS, Service Data Reference Table .)

Q. Is the check result normal?
Go to Step 4.
Diagnose the ETACS-ECU. (Refer to GROUP 54A - ETACS, Trouble Symptom Chart for Input Signal .)

STEP 4. M.U.T.-III data list
Check the OSS-ECU data list.

  • Operate the brake pedal.
Operation state
 Item No.
 Check item
 Display
Brake pedal is depressed
 3
 Stop lamp switch
 ON
Brake pedal released
 OFF
OK: Operation state and data list display agree with each other.

Q. Is the check result normal?
Go to Step 5.
Replace the OSS-ECU and register the chassis number (Refer to ).

STEP 5. Check whether the diagnosis code is reset.

Q. Is the diagnosis code set?
Replace the OSS-ECU and register the chassis number (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).