2. Check Harness Continuity

1. Turn ignition switch OFF.
2. Disconnect auto trunk control unit and auto trunk motor connectors.
3. Check continuity between auto trunk control unit connector B111 terminals 20, 21 and auto trunk motor connector B109 terminals 6, 7.
   1. 20 (G/W) - 7 (G/W) : Continuity should exist  .
   2. 21 (L/W) - 6 (L/W) : Continuity should exist  .
4. Check continuity between auto trunk motor connector B109 terminals 6, 7 and ground.
   1. 6 (L/W) - Ground : Continuity should not exist  .
   2. 7 (G/W) - Ground : Continuity should not exist  .

OK or NG 

1. OK : Replace auto trunk motor.
2. NG : Repair or replace harness between auto trunk control unit and auto trunk motor.

Fig 1: Checking Harness Continuity

Courtesy of NISSAN MOTOR CO., U.S.A.