NO.9 NO AUDIO SYSTEM ILLUMINATION [ENTIRE AUDIO SYSTEM]

id0903e2826600

9 | No audio system illumination
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Possible DTC | Using the M-MDS | U3003:16
Without using M-MDS (On-board diagnostic test mode) | 09:Er20
Possible cause | • Illumination turned off by panel light control switch operation • Open or short circuit in TNS signal wiring harness • Poor connection of audio unit connector, terminal damage • Audio unit malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | • Has the panel light control switch been operated? | Yes | Go to the next step.
No | The system is normal. Explain to the customer that the illumination is turned off by the panel light control switch operation.
2 | • Disconnect the audio unit connector (24-pin) and inspect the continuity between the audio unit wiring harness-side connector terminal 1G (TNS) and the ground. • Is there continuity? | Yes | Repair or replace the short circuit in the suspect wiring harness. After repair the harness, replace with the appropriate standard fuse.
No | Go to the next step.
3 | • Inspect the connection of the audio unit connector (24-pin). • Inspect both the audio unit and wiring harness-side connector terminal 1G for poor connection (such as damaged/pulled-out pins, corrosion). • Are all the pins normal? | Yes | Go to the next step.
No | If poor connection of audio unit connector: • Securely connect the audio unit connector. If the audio unit side connector is wrong: • Replace the audio unit. (See AUDIO UNIT REMOVAL/INSTALLATION.) If the wiring harness-side connector is wrong: • Repair or replace the pins and/or the connector.
4 | • Connect the audio unit connector (24-pin). • Turn the ignition switch to the ACC position. • Inspect the voltage at the audio unit connector terminal 1G (TNS). • Is the voltage B+ when the light switch is turned to the TNS position? | Yes | Replace the audio unit. (See AUDIO UNIT REMOVAL/INSTALLATION.)
No | Repair or replace the suspect wiring harness (TNS signal).