INSPECTION PROCEDURE P-22: 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.

  • Interior lamps
  • Interior lamp automatic-shutdown function

POSSIBLE CAUSES

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

DIAGNOSIS PROCEDURE

Step 1. ECU check by using the SWS monitor
Check that the power supply and earth lines to the ETACS-ECU and the SWS communication lines are normal.

  • Ignition switch: OFF
ECUS TO BE CHECKED
  • ETACS ECU
OK: "OK" is displayed on the "ETACS ECU" menu.

Q. Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is impossible ."

Step 2. Connector check: C-219 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 3.

Repair the defective connector.

Step 3. Voltage measurement at the C-219 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 C-219 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 C-219 ETACS-ECU connector terminal No.8 and the ignition switch (IG1).




note Prior to the wiring harness inspection, check junction block connector C-202, 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 C-219 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 C-219 ETACS-ECU connector terminal No.4 and the ignition switch (ACC).








note Prior to the wiring harness inspection, check joint connector C-32 <LH drive vehicles>, C-01 <RH drive vehicles> junction block connector C-203 or intermediate connector C-125, 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. Pulse check
Check the input of the interior lamp loaded signal.
System switch
 Check condition
Interior lamp loaded signal
 When a load is applied through multi-purpose fuse No.18
OK: The M.U.T.-III sounds or the voltmeter needle fluctuates.

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.