DTC Troubleshooting: B1390

DTC B1390: Tailgate Closer Unit Malfunction Clear the DTCs using the HDS. 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 Step 3 .
NO | - | Go to Step 4 .
Check the DTCs by selecting the DTCs MENU (DTCs) from the HDS. Is DTC B1390 indicated?
YES | - | Go to Step 15 .
NO | - | Intermittent failure, the system is OK at this time.■
Cycle the ignition switch to OFF. Open the tailgate fully with emergency lever of inner side of tailgate. Disconnect power tailgate control unit connector A (26P). Disconnect the tailgate closer unit 12P connector. 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 Step 9 .
NO | - | Repair an open in the RED/BLU (CLM+) or BLK/RED (CLM−) wire.■
Disconnect power tailgate control unit connector B (5P). |

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 Step 11 .
NO | - | Go to Step 21 .

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 Step 12 .
NO | - | Repair an open in the BLK (PG2) wire or poor ground (G705).■
By using the screwdriver, close the latch in the tailgate. Reconnect the tailgate closer unit 12P connector. |

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.■
NO | - | Faulty tailgate closer motor; replace it.■
Check the DTCs by selecting the DTCs MENU (DTCs) from the HDS. Is B1380, B1381, B1382, or B1384 display?
YES | - | Go to DTC troubleshooting.■
NO | - | Go to Step 16 .
Cycle the ignition switch to OFF. Open the tailgate fully. |

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.■
NO | - | Go to Step 19 .
Disconnect the tailgate closer unit 12P connector. |

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.■
NO | - | Faulty half 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.■
Reconnect the tailgate closer unit 12P connector. |

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 Step 23 .
NO | - | Go to Step 25 .
Disconnect the tailgate closer unit 12P connector. |

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

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