U128F

DTC Troubleshooting: U128F

DTC U128F:

Gauge Control Module Lost Communication With BSI Control Unit (BSI Message)

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. Clear the DTCs with the HDS.

2. Press the engine start/stop button to select the OFF, ACC and ON mode.

3. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U128F indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the gauge control module and the BSI control unit.

5. From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS.

Is the BSI control unit detected?

YES -

Go to step 10.

NO -

Go to step 6.

6. Measure the voltage between body ground and BSI control unit 16P connector terminal No. 10.





Is there battery voltage?

YES -

Go to step 9.

NO -

Go to step 7.

7. Press the engine start/stop button to select the OFF mode.

8. Check the No. 1 (7.5 A) fuse in the driver's under-dash fuse/relay box.

Is the fuse OK?

YES -

Repair an open or high resistance in the No. 1 (7.5 A) fuse circuit.

NO -

Replace the fuse. If the fuse blows again, repair a short to ground in the No. 1(7.5 A) fuse circuit.

9. Measure the voltage between body ground and BSI control unit 16P connector terminal No. 7.





Is there less than 0.2 V?

YES -

Go to step 10.

NO -

Repair an open or high resistance in the ground wire or poor ground (G601).

10. Press the engine start/stop button to select the OFF mode.

11. Disconnect the BSI control unit 16P connector.

12. Disconnect gauge control module connector A (32P).

13. Check for continuity between gauge control module connector A (32P) terminals No. 29 and No. 30 and BSI control unit 16P connector terminals No. 5 and No. 6 respectively.





Is there continuity?

YES -

Replace the BSI control unit BSI Control Unit Removal/Installation.

NO -

Repair an open or poor connection in the B-CAN wire(s) between the BSI control unit and the gauge control module.