DTC Troubleshooting: B1390

DTC B1390:  Tailgate Closer Unit Malfunction


1.Clear the DTCs by selecting the DTCs MENU (DTCs) from the Honda PGM Tester or the HDS.

2.Close the tailgate fully, then operate the tailgate outer handle, for more than 10 seconds. Check the un-locking operation.

Is there operation sound?


YES - Go to 3.


NO - Go to 4.


3.Check the DTCs by selecting the DTCs MENU (DTCs) from the Honda PGM Tester or the HDS.

Is DTC B1390 indicated?


YES - Go to 15.


NO - Intermittent failure, the system is OK at this time.n


4.Cycle the ignition switch to OFF.

5.Open the tailgate fully with emergency lever of inner side of tailgate.

6.Disconnect power tailgate control unit connector A (26P).

7.Disconnect the tailgate closer unit 12P connector.

8.Check for continuity between the No. 13 terminal of power tailgate control unit connector A (26P) and the No. 1 terminal of the tailgate closer unit 12P connector, the No. 26 terminal of power tailgate control unit connector A (26P) and the No. 2 terminal of the tailgate closer unit 12P connector.

Is there continuity?


YES - Go to 9.


NO - Repair an open in the RED/BLU (CLM+) or BLK/RED (CLM-) wire.n


9.Disconnect power tailgate control unit connector B (5P).

10.Check for voltage between the No. 1 terminal of power tailgate control unit connector B (5P) and body ground.

Is there battery voltage?


YES - Go to 11.


NO - Go to 21.


11.Check for continuity between the No. 3 terminal of power tailgate control unit connector B (5P) and body Ground.

Is there continuity?


YES - Go to 12.


NO - Repair an open in the BLK (PG2) wire or poor ground (G705).n

12.By using the screwdriver, close the latch in the tailgate.

13.Reconnect the tailgate closer unit 12P connector.

14.Connect battery positive (+) terminal to the No. 13 terminal of power tailgate control unit connector A (26P), and connect battery negative (-) terminal to the No. 26 terminal, operate the tailgate closer motor for close.
(less than one second), then reverse connect and operate.

Is there smooth rotation?


YES - Faulty power tailgate control unit; replace it.n


NO - Faulty tailgate closer motor; replace it.n


15.Check the DTCs by selecting the DTCs MENU (DTCs) from the Honda PGM Tester or the HDS.

Is B1380, B1381, B1382, or B1384 display?


YES - Go to DTC troubleshooting.


NO - Go to 16.

16.Cycle the ignition switch to OFF.

17.Open the tailgate fully.

18.Check for continuity between the No. 20 terminal and the No. 14 terminal of the power tailgate control unit connector A (26P), and the No. 18 terminal and the No. 14 terminal.

Is there continuity?


YES - Faulty power tailgate control unit; replace it.n


NO - Go to 19.


19.Disconnect the tailgate closer unit 12P connector.

20.Check for continuity between the No. 6 terminal and the No. 9 terminal of the tailgate closer unit 12P connector, and the No. 7 terminal and the No. 9 terminal.

Is there continuity?


YES - Repair an open in the BLU/RED (HALF) or the BLU/BLK (LATCH) wire between the power tailgate control unit and the tailgate closer unit.n


NO - Faulty harf latch or full latch switch; replace the tailgate closer unit, or repair an open in the BLU/RED (HALF) or the BLU/BLK (LATCH) wire.n

21.Reconnect the tailgate closer unit 12P connector.

22.Check for continuity between the No. 13 and No. 26 terminals of power tailgate control unit connector A (26P) and body ground.

Is there continuity?


YES - Go to 23.


NO - Go to 25.


23.Disconnect the tailgate closer unit 12P connector.

24.Check for continuity between the No. 13 and No. 26 terminals of power tailgate control unit connector A (26P) and body ground.

Is there continuity?


YES - Repair a short in the RED/BLU (CLM+) or the BLK/RED (CLM-) wire, or faulty tailgate closer motor; replace the tailgate closer unit.n


NO - Repair a short in the RED/BLU (CLM+) or the BLK/RED (CLM-) wire between the power tailgate control unit and the tailgate closer unit.n

25.Disconnect the power tailgate control unit connector C (4P).

26.Check for continuity between the No. 3 terminal of power tailgate control unit connector C (4P) and body ground.

Is there continuity?


YES - Repair a short in the BRN/BLK (CLU+) wire.n


NO - Repair an open in the WHT/YEL (VMP2) wire, or blown No. 41 (20A) fuse in the under-hood subfuse box.n