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

id0903e2803600

7 | ALC function is inoperative
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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
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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.