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


COMMENTS ON TROUBLE SYMPTOM


If the stop lamps do not illuminate or go out normally, the stop lamp switch input signal circuit, or the stop lamps may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


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


Temporarily replace the stop lamp relay, and then depress the brake pedal.
Item No.
 Item name
 Normal condition
Item 290
 Stop lamp switch
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 2.

Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 12 "The stop lamp switch signal is not received."

STEP 2. Check the bulb of the stop lamps


Check the bulb of the defective lamps.

Q. Is the check result normal?

Go to Step 3.

Replace the bulb of the defective lamps.

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?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Go to Step 4.

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?

Go to Step 5.

Repair the connector(s) or wiring harness.

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?

Go to Step 7.

Go to Step 6.

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?

Go to Step 7.

Repair the connector(s) or wiring harness.

STEP 7. Retest the system


Check that the stop lamps illuminates normally.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the stop lamps.