Uart Communication Line Circuit Check

CHECK UART LINE HARNESS
1. Turn ignition switch OFF.
2. Disconnect driver seat control unit connector and automatic drive positioner control unit connector.
3. Check continuity between driver seat control unit connector B152 terminal 2, 8 and automatic drive positioner connector M49 terminal 10, 26.
  1. 2 (P) - 26 (W) : Continuity should exist.
  2. 8 (G/Y) - 10 (B) : Continuity should exist.
4. Check continuity between driver seat control unit connector B152 terminal 2, 8 and ground.
  1. 2 (P) - Ground : Continuity should not exist.
  2. 8 (G/Y) - Ground : Continuity should not exist.
Fig 1: Checking Continuity Between Terminal 2, 8 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK : GO TO 2.
2. NG : Repair or replace harness between driver seat control unit and automatic drive positioner.
CHECK UART LINE SIGNAL 1
1. Turn ignition switch ON.
2. Check signal between driver seat control unit connector ground, with oscilloscope.
  
  Fig 2: Signal Table
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Checking Signal Between Terminal 2 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 3.
2. NG : Check the flowing.
  - When voltage signal dose not appear with a constant voltage (approx. 5V), replace driver seat control unit.
  - When voltage signal dose not appear with a constant voltage (approx. 0V), replace automatic drive positioner control unit.
CHECK UART LINE SIGNAL 2
Check signal between automatic driver positioner control unit connector ground, with oscilloscope.

Fig 4: Signal Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 5: Checking Signal Between Automatic Driver Positioner Control Unit Connector Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK : GO TO 4.
2. NG : Check the flowing.
  - When voltage signal dose not appear with a constant voltage (approx. 5V), replace automatic driver seat control unit.
  - When voltage signal dose not appear with a constant voltage (approx. 0V), replace driver seat control unit.
CHECK DRIVER SEAT CONTROL UNIT
Dose the automatic drive positioner operate, when the driver control unit exchanged?

Does seat memory function operate?
1. YES : Replace automatic drive positioner control unit.
2. NG : Replace driver seat control unit.