Code No.B1136 Stop lamp switch

caution

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

DIAGNOSTIC FUNCTION

When the stop lamp switch status is different from the brake switch information received from ETACS-ECU via CAN, KOS&OSS-ECU sets diagnosis code No.B1136, and displays the power supply system error warning the combination meter, and flashes the indicator of engine switch in orange.

JUDGEMENT CRITERIA

Check Conditions

After KOS&OSS-ECU activation

Judgement Criterion

The difference between the stop lamp switch condition and the stop lamp switch information has been detected.
The stop lamp 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 earth or open circuit between stop lamp switch and KOS&OSS-ECU or between stop lamp switch and ETACS-ECU)
ETACS-ECU malfunction
Malfunction of KOS&OSS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

After performing the forced power supply output (Refer to

) "IG-ON" using the M.U.T.-III, diagnose the CAN bus line.

Q. Is the check result normal?

Go to Step 2.

Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting

STEP 2. Check of short to earth or open circuit in STP1 line between stop lamp switch connector and KOS&OSS-ECU connector

Q. Is the check result normal?

Go to Step 3.

Repair the connector(s) or wiring harness.

STEP 3. Check of short to earth or open circuit in BKLP line between stop lamp switch connector and ETACS-ECU connector

Q. Is the check result normal?

Go to Step 4.

Repair the connector(s) or wiring harness.

STEP 4. M.U.T.-III other system data list

Check the ETACS-ECU data list.

Item No.108: Stop lamp switch (Refer to GROUP 54A - ETACS, Service Data Reference Table ).

Q. 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. M.U.T.-III data list

Check the KOS&OSS-ECU data list.

Operate the brake pedal.

Item No.	Check item	Operation state	Display
22	Stop lamp switch	Brake pedal is depressed	ON
22	Stop lamp switch	Brake pedal released	OFF

OK: Operation state and data list display agree with each other.

Q. Is the check result normal?

Go to Step 6.

Replace the KOS&OSS-ECU and register the chassis number (Refer to

STEP 6. Check whether the diagnosis code is set again.

Q. Is the diagnosis code set?

Replace the KOS&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