Inspection Procedure 3: The stop lamps do not illuminate or go out normally.


COMMENTS ON TROUBLE SYMPTOM


*
note *: The stop lamp relay cannot be inspected because it is a semiconductor relay.

PROBABLE CAUSES



  • Malfunction of stop lamp switch
  • Malfunction of stop lamp relay
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Connector check: C-29 stop lamp relay connector


Q. Is the check result normal?





STEP 2. Resistance measurement at the C-29 stop lamp relay connector


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between stop lamp relay connector terminal No. 5 and the body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?





STEP 3. Wiring harness check between the C-29 stop lamp relay connector terminal No. 5 and the body earth.



  • Check the earth wires for open circuit.

Q. Is the check result normal?





STEP 4. Check the stop lamp switch.



Q. Is the check result normal?





STEP 5. Voltage measurement at the C-29 stop lamp relay connector


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between stop lamp relay connector terminal No. 4 and the body earth.
OK: System voltage
(3)Stop lamp switch: ON
(4)Measure the voltage between stop lamp relay connector terminal No. 7 and the body earth.
OK: System voltage

Q. Is the check result normal?





STEP 6. Connector check: C-403 ETACS-ECU connector


Q. Is the check result normal?





STEP 7. Wiring harness check between the C-29 stop lamp relay connector terminal No. 4/7 and the C-403 ETACS-ECU connector terminal No.1.



  • Check the power supply line for open circuit and short circuit.

Q. Is the check result normal?





STEP 8. Connector check: C-410 ETACS-ECU connector


Q. Is the check result normal?





STEP 9. Measure the voltage at the C-410 ETACS-ECU connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Disconnecting the C-29 stop lamp relay connector.
(3)Stop lamp switch: ON
(4)Measure the voltage between ETACS-ECU connector terminal No. 16 and the body earth.
OK: system voltage

Q. Is the check result normal?





STEP 10. Check the wiring harness between C-410 ETACS-ECU connector terminal No.16 and C-29 stop lamp relay connector terminal No.7



  • Check the signal line for short circuit.

Q. Is the check result normal?





STEP 11. Wiring harness check between the C-29 stop lamp relay connector terminal No. 2 and the C-28 intermediate connector terminal No.24.



  • Check the output line for open circuit and short circuit.

Q. Is the check result normal?





STEP 12. Retest the system



Q. Is the check result normal?