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 power tailgate system is OK at this time. Check for loose or poor connections at the power tailgate control unit connectors, and at the power tailgate drive unit connector.�

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. Using jumper wires, connect battery power to power tailgate control unit connector A (5P) terminal No. 3 (or No. 5) and ground the terminal No. 5 or (No. 3).





10. Check for motor operation.

Does the motor run normally?

YES -

Go to step 11.

NO -

Faulty power tailgate motor, replace the power tailgate 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. 9 and No. 20 and body ground individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 13.

13. Using jumper wires, connect battery power to power tailgate control unit connector B (20P) terminal No. 9 and ground the terminal No. 20. Check for clutch operation.





Can you hear the clutch operate?

YES -

Go to step 14.

NO -

Faulty power tailgate clutch, replace the power tailgate 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. 4 (40 A) fuse in the auxiliary under-hood fuse box. If the fuse is OK, check for an open or high resistance in the wire between the auxiliary under-hood fuse 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. 17 (20 A) fuse in the driver's under-dash fuse/relay box. If the fuse is OK, check for an open or high resistance in the wire between the driver's under-dash fuse/relay box and the power tailgate control unit.�

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





Is there continuity?

YES -

Replace the power tailgate control unit.�

NO -

Repair an open in the wire or poor ground (G702) or an open the ground wire.�