SUSPENSION CONTROL UNIT: Diagnosis Procedure

Regarding Wiring Diagram information, refer to "WIRING DIAGRAM ".

1. CHECK FUSES 

   Check that the following fuses of the suspension control unit are not are not blown.

   Unit	Terminals	Signal name	Fuse No.
   Suspension control unit	7	Battery power	29
   	6	Ignition switch ON or START	12

   Are the fuses OK? 

   YES: GO TO 2.

   NO: If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.

2. POWER SUPPLY CIRCUIT CHECK 
   1. Disconnect suspension control unit connector B3.
   2. Check voltage between the suspension control unit connector B3 and ground.

      (+)		(-)	OFF	ACC	ON
      Connector	Terminal
      B3	7	Ground	Battery voltage	Battery voltage	Battery voltage
      	6	Ground	0V	0V	Battery voltage

      Fig 1: Checking Voltage Between Suspension Control Unit Connector B3 And Ground

      Courtesy of NISSAN NORTH AMERICA, INC.

      Are the voltage results as specified? 

      YES: GO TO 3.

      NO:

      • Check connector housings for disconnected or loose terminals.
      • Repair harness or connector.
3. GROUND CIRCUIT CHECK 
   1. Turn ignition switch OFF.
   2. Check continuity between suspension control unit harness connector B3 and ground.

      Connector	Terminal	-	Continuity
      B3	16	Ground	Yes

      Is continuity present? 

      YES: Inspection End.

      NO: Repair harness or connector.

      Fig 2: Checking Continuity Between Suspension Control Unit Harness Connector B3 And Ground

      Courtesy of NISSAN NORTH AMERICA, INC.