A/C Operation Is Not Possible

WARNING: This page is about a different car, the 2003 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

HARNESS CHECK
1. Turn ignition switch OFF.
2. Disconnect A/C auto amp. connector and AV and NAVI control unit connector.
3. Check continuity between A/C auto amp. and AV and NAVI control unit.
  
  Fig 1: Electrical Testing Specifications (A/C Operation Is Not Possible - 1 Of 2)
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check continuity between AV and NAVI control unit and ground.
  
  Fig 2: Electrical Testing Specifications (A/C Operation Is Not Possible - 2 Of 2)
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Harness Check (A/C Operation Is Not Possible)
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK >> GO TO 2.

NG >> Repair harness.
AV-A/C, AC-CLK COMMUNICATION SIGNAL CHECK
1. Connect A/C auto amp. connector.
2. Turn ignition switch ON.
3. Check voltage between AV and NAVI control unit harness connector B29 terminal 38 (L) and ground.
  1. Approx. 3.5 or more
OK or NG

OK >> GO TO 3.

NG >> Replace A/C auto amp.

Fig 4: A/C-AV, AC-CLK Communication Signal Check When A/C Operation Is Not Possible (At AV & NAVI Control Unit)
Courtesy of NISSAN MOTOR CO., U.S.A.
AV-A/C, AC-CLK COMMUNICATION SIGNAL CHECK
1. Connect AV and NAVI control unit connector.
2. Turn ignition switch ON.
3. Check the signal between AV and NAVI control unit harness connector B29 terminal 38 (L), 39 (L/R) and ground with CONSULT-II or oscilloscope.
  1. 38 (L), 39 (L/R) - ground : Refer to " TERMINALS AND REFERENCE VALUE FOR AV AND NAVI CONTROL UNIT " .
OK or NG

OK >> Replace A/C auto amp.

NG >> Replace AV and NAVI control unit.

Fig 5: Checking A/C-AV, AC-CLK Communication Signal Check When A/C Operation Is Not Possible W/ CONSULT-II (At AV & NAVI Control Unit)
Courtesy of NISSAN MOTOR CO., U.S.A.