B1388

DTC Troubleshooting: B1388

DTC B1388:

Power Tailgate Drive Motor Circuit Malfunction

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. Open the tailgate.

2. Close the tailgate automatically with the keyless transmitter or inside tailgate switch.

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

4. Clear the DTCs with the HDS.

5. Check for DTCs with the HDS.

Is DTC B1388 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 drive unit.�

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

7. Disconnect drive unit connector A (2P).

8. Check for continuity between power tailgate control unit connector A (5P) terminals No. 3 and No. 5 and body ground individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 9.

9. Connect battery power to power tailgate control unit connector A (5P) terminal No. 5 (or No. 3) and ground the terminal No. 3 or (No. 5).





10. Check the power tailgate motor operation.

Does the motor run normally?

YES -

Go to step 11.

NO -

Faulty power tailgate motor, replace the drive unit Service and Repair.�

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

12. Check for continuity between power tailgate control unit connector B (20P) terminals No. 1 and No. 2 and body ground individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 13.

13. Connect battery power to the power tailgate control unit connector B (20P) terminal No. 2 and ground to terminal No. 1. Check for clutch operation.





Can you hear the clutch operate?

YES -

Go to step 14.

NO -

Faulty power tailgate clutch, replace the drive unit Service and Repair.�

14. Measure the voltage between power tailgate control unit connector A (5P) terminal No. 2 and body ground.





Is there battery voltage?

YES -

Go to step 15.

NO -

Check the No. 1 (40 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 the power tailgate control unit.�

15. 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 16.

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 the power tailgate control unit.�

16. Check for continuity between body ground and power tailgate control unit connector A (5P) terminals No. 1 and No. 4 individually.





Is there continuity?

YES -

Replace the power tailgate control unit Service and Repair.�

NO -

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