Inspection Procedure 4: Audio illuminations does not work normally.


caution Before replacing the radio and CD player, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM


If the tail lamps illuminate, illumination signal is sent from the ETACS-ECU to the radio and CD player. This switches the illumination of the radio and CD player from day mode to night mode. When the rheostat knob is operated, the combination meter will send "ILL-" signal to the radio and CD player accordingly. The illumination on the radio and CD player will be changed according to this signal. If the mode is switched, the illumination signal line, the ETACS-ECU, the combination meter or the radio and CD player may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check that the tail lamps illuminate.


Q. Is the check result normal?

Go to Step 2.

Diagnose the tail lamps. (Refer to .)

STEP 2. Check of short to power supply, short to earth, and open circuit in ILL+ line between radio and CD player connector and ETACS-ECU (tail lamp relay).


Q. Is the check result normal?

Go to Step 3.

Repair the connector(s) or wiring harness.

STEP 3. Combination meter illumination check.


When the rheostat knob is operated with the mechanical switch illuminated, the illumination should be changed.

Q. Is the check result normal?

Go to Step 4.

Diagnose the combination meter. (Refer to .)

STEP 4. Check of short to power supply, short to earth, and open circuit in ILL- line between radio and CD player connector and combination meter.


Q. Is the check result normal?

Go to Step 5.

Repair the connector(s) or wiring harness.

STEP 5. Substitute the ETACS-ECU with good one, and check the trouble symptom.


Substitute the ETACS-ECU with good one. When the tail lamps illuminate, check that the illumination of the radio and CD player is switched from day mode to night mode.

Q. Is the check result normal?

Replace the ETACS-ECU.

Replace the radio and CD player.