Inspection Procedure C-21: The interior lamp loaded signal is not detected.


caution Whenever the ECU is replaced, ensure that the input signal circuit is normal.














COMMENTS ON TROUBLE SYMPTOM
The interior lamp automatic-shutdown function operates in accordance with the interior lamp loaded signal. If this signal is abnormal, the functions below will not work normally.

  • Ignition key cylinder illumination lamp
  • Room lamps

PROBABLE CAUSES

  • Malfunction of the ETACS-ECU
  • Damaged wiring harness or connector(s)

DIAGNOSIS PROCEDURE

STEP 1. Check the power supply circuit.
When the ignition switch is turned to the LOCK (OFF) position, check if the hazard warning lamps illuminate.

Q. Is the check result normal?
Go to Step 2.
Refer to inspection procedure A-1 "Check the ETACS-ECU battery power supply circuit <Not using SWS monitor> or <Using SWS monitor>."

STEP 2. Connector check: D-419 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 3.
Repair the defective connector.

STEP 3. Voltage measurement at the D-419 ETACS-ECU connector.
(1)Remove the ETACS-ECU, and measure at the junction block side.
(2)Turn the ignition switch to the ON position.
(3)Voltage between D-419 ETACS-ECU connector terminal No.8 and body earth
OK: System voltage

Q. Is the check result normal?
Go to Step 5.
Go to Step 4.

STEP 4. Check the wiring harness between D-419 ETACS-ECU connector terminal No.8 and the ignition switch (IG1).
note Prior to the wiring harness inspection, check junction block connector D-403, and repair if necessary.

  • Check the power supply line to the ignition switch (IG1) for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 5. Voltage measurement at the D-419 ETACS-ECU connector.
(1)Remove the ETACS-ECU, and measure at the junction block side.
(2)Turn the ignition switch to the ACC position.
(3)Voltage between terminal 4 and body earth
OK: System voltage

Q. Is the check result normal?
Go to Step 7.
Go to Step 6.

STEP 6. Check the wiring harness between D-419 ETACS-ECU connector terminal No.4 and the ignition switch (ACC).
note Prior to the wiring harness inspection, check junction block connector D-401 and intermediate connectors D-238 and D-241, and repair if necessary.

  • Check the power supply line to the ignition switch (ACC) for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 7. Retest the system.
Check that the interior lamp loaded signal is received normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.