Inspection Procedure P-20: The interior lamp "all on" or "all off" switch signal is not sent to the ETACS-ECU.


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


COMMENTS ON TROUBLE SYMPTOM
Input signals from the interior lamp "ON" and "OFF" switch are used to operate the interior lamps (room lamp, rear personal lamp, luggage compartment lamp, door lamps and key illumination lamp). If the signals are abnormal, the interior lamps will not illuminate and extinguish normally.

POSSIBLE CAUSES

  • Malfunction of the room lamp (interior lamp switch)
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSTIC PROCEDURE

Step 1. Connector check: E-02 room lamp connector




Q. Is the check result normal?

Go to Step 2.

Repair the connector.

Step 2. Check the Check the room lamp.
Refer to GROUP 54A - Room lamp .

Q. Is the check result normal?
Go to Step 3.
Replace the room lamp.

Step 3. Resistance measurement at the E-02 room lamp connector.




(1)Disconnect the connector, and measure at the wiring harness side.

(2)Resistance between E-02 room lamp connector terminal No.5 and body earth
OK: 2Ω or less

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

Step 4. Check the wiring harness between E-02 room lamp connector terminal No.5 and body earth






note Prior to the wiring harness inspection, check intermediate connector E-11, and repair if necessary.

  • Check the earth wires 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. Connector check: C-221 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

Step 6. Check the wiring harness from E-02 room lamp connector terminal Nos. 6 and 7 to C-221 ETACS-ECU connector terminal Nos. 53 and 63.










note Prior to the wiring harness inspection, check intermediate connector E-11 and C-128, and repair if necessary.

  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

Step 7. Retest the system.
Check that the room lamp 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.