B1390

DTC Troubleshooting: B1390

DTC B1390:

Power Tailgate Closer Motor Function Error

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. With the tailgate closed, pull the tailgate outer handle and wait for 10 seconds.

2. Turn the ignition switch to LOCK (0) and then back to ON (II).

3. Clear the DTCs with the HDS.

4. Listen for the sound of the latch releasing.

Is there sound?

YES -

Go to step 5.

NO -

Go to Step 7.

5. Check for DTCs with the HDS.

Is DTC B1390 indicated?

YES -

Go to step 6.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the power tailgate control unit and the closer motor.�

6. Check for DTCs with the HDS.

Are DTCs B1380, B1381, B1382, B1383, and/or B1384 also indicated?

YES -

Troubleshoot the indicated DTCs.�

NO -

Replace the power tailgate control unit Service and Repair and recheck the system.�

7. Turn the ignition switch to LOCK (0).

8. Open the tailgate.

9. Disconnect the 2P connector from the power tailgate closer motor.

10. Disconnect power tailgate control unit connector B (20P).

11. Check for continuity between power tailgate control unit connector B (20P) terminals No. 9 and No. 20 and power tailgate closer motor 2P connector terminals No. 2 and No. 1 respectively.





Is there continuity?

YES -

Go to step 12.

NO -

Repair an open or high resistance in the wire.�

12. Measure the voltage between power tailgate control unit connector B (20P) terminal No. 12 and body ground.





Is there battery voltage?

YES -

Go to step 14.

NO -

Check the No. 8 (20 A) fuse in the auxiliary under-hood fuse/relay box. If the fuse is OK, check for an open in the wire between the auxiliary under-hood fuse/relay box and power tailgate control unit.�

13. Disconnect power tailgate control unit connector A (5P).

14. Check for continuity between power tailgate control unit connector A (5P) terminal No. 4 and body ground.





Is there continuity?

YES -

Go to step 15.

NO -

Repair an open or high resistance in the wire or poor ground (G602).�

15. Turn the tailgate lock latch to the fully-closed position using a screwdriver.

16. Reconnect the power tailgate closer motor 2P connector.

17. Connect battery power to power tailgate control unit connector B (20P) terminal No. 20 (or No. 9) and ground terminal No. 9 (or No. 20) momentarily.





Does the motor run smoothly?

YES -

Replace the power tailgate control unit Service and Repair.�

NO -

Go to step 18.

18. Reconnect the 6P connector to the power tailgate closer unit.

19. Check for continuity between body ground and power tailgate control unit connector B (20P) terminals No. 9 and No. 20 individually.





Is there continuity?

YES -

Go to step 20.

NO -

Go to step 22.

20. Disconnect the 6P connector from the power tailgate closer unit.

21. Check for continuity between body ground and power tailgate control unit connector B (20P) terminals No. 9 and No. 20 individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Replace the power tailgate latch assembly Tailgate Latch Replacement.�

22. Check for continuity between power tailgate control unit connector B (20P) terminal No. 2 and body ground.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Check the No. 8 (20 A) fuse in the auxiliary under-hood fuse/relay box. If the fuse is OK, check for an open in the wire between the auxiliary under-hood fuse/relay box and power tailgate control unit.�