Audio System Symptom Troubleshooting - Audio unit button illumination does not work (without navigation system)
With the headlight switch still on, measure the voltage between the audio unit connector A (24P) terminal No. 13 and body ground.
Is there battery voltage?
YES
-
Check the connections at the audio unit connector A (24P). If all connections are OK,
substitute a known-good audio unit
and recheck. If the symptom/indication goes away,
replace the original audio unit.
■
NO
-
Repair open in the wire between the passenger's under-dash fuse/relay box and audio unit.■