NO.7 ALC FUNCTION IS INOPERATIVE [ENTIRE AUDIO SYSTEM]

id0903e2803600

7

ALC function is inoperative

Possible DTC

—
POSSIBLE CAUSE
•  Audio unit malfunction
•  Open or short circuit in vehicle speed signal wiring harness (e. g., instrument cluster)
Note
•  Inspect the ALC function while driving the vehicle and playing a CD.

Diagnostic procedure

STEP

INSPECTION

ACTION
1
•  Turn the ALC function on.
•  Inspect the ALC function operation while driving the vehicle. (ALC level 3)
•  Does the ALC system operate properly?.
Yes
The system is normal. Explain the ALC function to the customer.
No
Go to the next step.
2
•  Turn the ignition switch to LOCK position.
•  Remove the audio unit.
•  Disconnect the audio unit connector (24-pin).
•  Inspect the audio unit connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
•  Are the terminals normal?
Yes
Go to the next step.
No
Repair or replace the terminal.
3
•  Turn the ignition switch to LOCK position.
•  Inspect for continuity between the following wiring harnesses.
―  1I terminal-GND
•  Is there continuity?
Yes
Repair or replace the wiring harness for a possible short to ground.
No
Go to the next step.
4
•  Turn the ignition switch to LOCK position.
•  Remove the instrument cluster.
•  Inspect for continuity following the wiring harness between instrument cluster and audio unit.
―  2O terminal-1I terminal
•  Is there continuity?
Yes
Replace the audio unit.
(See CENTER PANEL UNIT REMOVAL/INSTALLATION.)
(See CENTER PANEL UNIT DISASSEMBLY/ASSEMBLY.)
No
Repair or replace the wiring harness for possible open circuit between the instrument cluster and the audio unit.