Code No.P1769: Stop lamp switch system <4M41, 6G7>






















OPERATION


The stop lamp switch judges whether the brake pedal is depressed or released, and sends the information to the ECU.

DIAGNOSIS CODE SET CONDITIONS


If the stop lamp remains on for consecutively five minutes or more while the vehicle is being driven or all the stop lamp bulbs are blown, it is judged that there is a short or open circuit in the stop lamp switch and diagnosis code No.P1769 is set.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check that the stop lamps illuminate and extinguish normally.
The stop lamps should illuminate when the brake pedal is depressed, and extinguish when released.

Q. Is the check result normal?
Go to Step 7.
Go to Step 2.

STEP 2. Check the brake pedal height.
Refer to GROUP 35A - On-vehicle Service, Brake Pedal Check and Adjustment .

Q. Is the check result normal?
Go to Step 3.
Adjust the brake pedal height.

STEP 3. Check the stop lamp switch.
Refer to GROUP 35A - Brake Pedal .

Q. Is the check result normal?
Go to Step 4.
Replace the stop lamp switch.

STEP 4. M.U.T.-III data list
Item 19: Stop lamp switch (Refer to data list reference table ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 5.

STEP 5. Connector check: D-134 stop lamp switch connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. Measure the voltage at stop lamp switch connector D-134.
Disconnect the connector, and measure the voltage between terminal No.2 and earth at the harness side.
OK: System voltage

Q. Is the check result normal?
Go to Step 7.
Go to Step 12.

STEP 7. Measure the voltage at A/T-ECU connector D-39 <4M4> or engine-A/T-ECU connector D-214 <6G7>.
(1)Connect stop lamp switch connector D-134.
(2)Measure the voltage between A/T-ECU connector D-39 terminal No.59 <4M4> and earth or engine-A/T-ECU connector D-214 terminal No.39 <6G7> and earth.
OK:

    Brake pedal depressed: System voltage
    Brake pedal not depressed: 1 V or less

Q. Is the check result normal?
Go to Step 8.
Go to Step 10.

STEP 8. Connector check: D-39 A/T-ECU connector <4M4> or D-214 engine-A/T-ECU connector <6G7>
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 9.
Repair the defective connector.

STEP 9. M.U.T.-III data list
Item 19: Stop lamp switch (Refer to data list reference table ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the A/T-ECU <4M4> or engine-A/T-ECU <6G7>.

STEP 10. Connectors check: D-113 J/C (6) <4M4>, D-230 intermediate connector, D-39 A/T-ECU connector <4M4> or D-214 engine-A/T-ECU connector <6G7>
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 11.
Repair the defective connector.

STEP 11. Check the harness between stop lamp switch connector D-134 terminal No.1 and A/T-ECU connector D-39 terminal No.59 <4M4> or engine-A/T-ECU connector D-214 terminal No.39 <6G7>.
Check the output line for short or open circuit.

Q. Is the check result normal?
Go to Step 9.
Repair the wiring harness.

STEP 12. Connector check: D-241 intermediate connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 13.
Repair the defective connector.

STEP 13. Check the harness between stop lamp switch connector D-134 terminal No.2 and battery.
Check the power supply line for short or open circuit.

Q. Is the check result normal?
Go to Step 9.
Repair the wiring harness.