Inspection Procedure 2: The stop lamps do not illuminate or go out normally.


COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of stop lamp switch input signal circuit
  • Malfunction of stop lamps
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III data list



Item No.
 Item name
 Normal condition
Item 290
 Stop lamp switch
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?





STEP 2. Check the bulb of the stop lamps



Q. Is the check result normal?





STEP 3. Resistance measurement at the stop lamp connectors (earth terminals).


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the rear combination lamp (LH) connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)
(3)Measure the resistance between the rear combination lamp (RH) connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)
(4)Measure the resistance between the high-mounted stop lamp connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?





STEP 4. Check of open circuit in earth line between the rear combination lamp (LH) connector, rear combination lamp (RH) connector, high-mounted stop lamp connector and body earth.


Q. Is the check result normal?





STEP 5. Voltage measurement at stop lamp connectors (power supply terminals).


(1)Remove the front fog lamp relay, and measure at the relay box side.
(2)Check the voltage between the rear combination lamp (LH) connector (power supply terminal) and body earth.
OK: System voltage
(3)Check the voltage between the rear combination lamp (RH) connector (power supply terminal) and body earth.
OK: System voltage
(4)Check the voltage between the high-mounted stop lamp connector (power supply terminal) and body earth.
OK: System voltage

Q. Is the check result normal?





STEP 6. Check of short to power supply, short to earth, and open circuit in STLO line between ETACS-ECU connector and rear combination lamp (LH) connector, rear combination lamp (RH) connector, high-mounted stop lamp connector.


Q. Is the check result normal?





STEP 7. Retest the system



Q. Is the check result normal?