Load Leveling Rear Air Suspension System Does Not Operate

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.

OK or NG
1. OK: GO TO 2.
2. NG: Carry out self-diagnosis. Refer to "SELF-DIAGNOSIS ".
CHECK FUSES
Check that the following fuses are not blown.

Fig 1: Trouble Diagnosis - Fuse Check Table
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 3.
2. NG: If fuse is blown, be sure to eliminate cause of problem before installing new fuse. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
CHECK SUSPENSION CONTROL UNIT POWER AND GROUND
1. Turn the ignition switch ON.
2. Check voltage between suspension control unit connector B3 terminal 6 (G/R) and ground and between suspension control unit connector B3 terminal 7 (W/L) and ground.
  1. Voltage: Approx. 12V
  Fig 2: Checking Voltage Between Suspension Control Unit Connector B3 Terminal 6 And Ground And Between Suspension Control Unit Connector B3 Terminal 7 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
Check resistance between suspension control unit connector B3 terminal 16 (B) and ground.
Continuity should exist.

OK or NG
1. OK: GO TO 4.
2. NG: Repair the circuit.
  
  Fig 3: Checking Resistance Between Suspension Control Unit Connector B3 Terminal 16 (B) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK GENERATOR SIGNAL INPUT
1. Start the engine.
2. Check voltage between suspension control unit connector B3 terminal 15 (BR/W) and ground.
  1. Voltage: Approx. 12V
  OK or NG
  1. OK: Replace the suspension control unit. Refer to "CONTROL UNIT ".
  2. NG: Repair the circuit.
    
    Fig 4: Checking Voltage Between Suspension Control Unit Connector B3 Terminal 15 (BR/W) And Ground
    Courtesy of NISSAN MOTOR CO., U.S.A.