Audio System Symptom Troubleshooting - USB device does not function (with navigation)
  1. Measure the voltage between USB adapter unit connector A (14P) terminal No. 11 and body ground.
Is there less than 0.1 V?
YES -
Check pin fit and connection substitute a known-good audio unit, and recheck. If the symptom/indication goes away, replace the original audio unit. If the symptom is still present, substitute a known-good USB adapter unit, and recheck. If the symptom/indication goes away, replace the original USB adapter unit. ■
NO -
Repair open in the wire between the USB adapter unit and the audio unit.■