Sound Signal Circuit between Navigation ECU and Multi-media Interface ECU: Procedure

1. Disconnect the F51 display and navigation module display connector.
2. Disconnect the L50 multi-media interface ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F51-1 (AGND) - L50-1 (USD1)	Always	Below 1 Ω
   F51-3 (VAR+) - L50-2 (URO+)	Always	Below 1 Ω
   F51-4 (VAL+) - L50-3 (ULO+)	Always	Below 1 Ω
   F51-7 (VA-) - L50-4 (UGD1)	Always	Below 1 Ω
   F51-1 (AGND) - Body ground	Always	10 kΩ or higher
   F51-3 (VAR+) - Body ground	Always	10 kΩ or higher
   F51-4 (VAL+) - Body ground	Always	10 kΩ or higher
   F51-7 (VA-) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   2