Diagnosis Procedure

1. CONNECTOR INSPECTION
   1. Disconnect ABS actuator and electric unit (control unit) connector and wheel sensor of malfunctioning code.
   2. Check terminals for deformation, disconnection, looseness or damage.

   Is the inspection result normal? 

   YES: GO TO 2

   NO: Repair or replace as necessary.

2. CHECK WHEEL SENSOR OUTPUT SIGNAL
   1. Connect ABS active wheel sensor tester (J-45741) to wheel sensor using appropriate adapter.
   2. Turn on the ABS active wheel sensor tester power switch.
      NOTE: The green POWER indicator should illuminate. If the POWER indicator does not illuminate, replace the battery in the ABS active wheel sensor tester before proceeding.
   3. Spin the wheel of the vehicle by hand and observe the red SENSOR indicator on the ABS active wheel sensor tester. The red SENSOR indicator should flash on and off to indicate an output signal.
   NOTE: If the red SENSOR indicator illuminates but does not flash, reverse the polarity of the tester leads and retest.

   Does the ABS active wheel sensor tester detect a signal? 

   YES: GO TO 3

   NO: Replace the wheel sensor. Refer to "REMOVAL AND INSTALLATION ".

3. CHECK TIRES

   Check for inflation pressure, wear and size of each tire.

   Are tire pressure and size correct and its tire wear within specifications? 

   YES: GO TO 4

   NO: Adjust tire pressure, or replace tire(s).

4. CHECK WHEEL BEARINGS

   Check wheel bearing axial end play. Refer to "INSPECTION " (front) or "ON-VEHICLE SERVICE " (rear).

   Is the inspection result normal? 

   YES: GO TO 5

   NO: Repair or replace as necessary. Refer to "REMOVAL AND INSTALLATION " (front) or "WHEEL BEARING (REAR) " (rear).

5. CHECK WIRING HARNESS FOR SHORT CIRCUIT
   1. Disconnect ABS actuator and electric unit (control unit) connector and wheel sensor of malfunctioning code.
   2. Check continuity between front wheel sensor connector terminals (A), rear wheel sensor connector terminals (B) and ground.
   Fig 1: Checking Continuity Between Wheel Sensor Connector Terminals And Ground
   Courtesy of NISSAN MOTOR CO., U.S.A.

   : Continuity should not exist. 

   Is the inspection result normal? 

   YES: GO TO 6

   NO: Repair the circuit.

6. CHECK WIRING HARNESS FOR OPEN CIRCUIT

Check continuity between ABS actuator and electric unit (control unit) connector and the malfunctioning wheel sensor connector E19, E41, C1 or C2.

Is the inspection result normal? 

YES: Replace the ABS actuator and electric unit (control unit). Refer to "REMOVAL AND INSTALLATION ".

NO: Repair the circuit.