Communication Line Check (Between Display Unit and NAVI Switch)

WARNING: This page is about a different car, the 2004 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK POWER SUPPLY AND GROUND CIRCUIT (DISPLAY UNIT)
1. Check power supply and ground circuit. Refer to POWER SUPPLY AND GROUND CIRCUIT CHECK FOR DISPLAY UNIT AND NAVI SWITCH .
OK or NG
1. OK: GO TO 2.
2. NG: Power supply and ground circuit check.
CHECK HARNESS
1. Turn ignition OFF.
2. Disconnect display unit connector and NAVI switch connector.
3. Check continuity between display unit harness connector M35 terminal 13 (R) and NAVI switch harness connector M37 terminal 4 (R).
  Continuity should exist.
4. Check continuity between display unit harness connector M35 terminal 13 (R) and ground.
  Continuity should not exist.
  
  Fig 1: Checking Continuity Between Display Unit Harness And NAVI Switch Harness
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
2. NG: Repair harness or connector.
COMMUNICATION SIGNAL CHECK
1. Connect display unit connector.
2. Turn ignition switch ON.
3. Check voltage between display unit harness connector M35 terminal 13 (R) and ground.
  13 (R) - Ground: Approx 5V
OK or NG
1. OK: Replace NAVI switch.
2. NG: Replace display unit.
  
  Fig 2: Checking Voltage Between Display Unit Harness Connector M35 Terminal 13 (R) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.