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B1079




DTC Troubleshooting: B1078, B1079

DTC B1078:

Daytime Running Light for Canada Circuit Malfunction

DTC B1079:

Daytime Running Light for America 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. Turn the ignition switch to ON (II).

2. Pull the parking brake lever.

3. Clear the DTCs with the HDS.

4. Release the parking brake lever.

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

6. Check for DTCs with the HDS.

Is DTC B1078 or B1079 indicated?

YES -

Go to step 7.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections.�

7. Turn the ignition switch to LOCK (0), and turn the headlight switch OFF.

8. Check the No. B28, No. B34 [No. B48], and No. B51 fuses in the under-dash fuse/relay box.

[ ]: Without HID

Are all fuses OK?

YES -

Go to step 9.

NO -

Replace the blown fuse, and recheck. If the No. B28 (20 A) fuse is blown again, replace the under-dash fuse/relay box. If the No. B34 (10A) [No. B48 (10 A)] or No. B51 (10 A) fuse is blown again, repair a short in the wire between the under-dash fuse/relay box and the appropriate headlight (high beam).�

9. Check the headlight bulbs.

Are the headlight bulbs OK?

YES -

Go to step 10.

NO -

Replace the bulb and recheck.�

10. Disconnect under-dash fuse/relay box connectors A (36P) and B (36P).

11. Disconnect both of the headlight (high beam) 2P connectors.

12. Check for continuity between right headlight (high beam) 2P connector terminal No. 2 and under-dash fuse/relay box connector A (36P) terminal No. 27.





Is there continuity?

YES -

Go to step 13.

NO -

Repair an open in the wire between the right headlight (high beam) and the under-dash fuse/relay box.�

13. Check for continuity between left headlight (high beam) 2P connector terminal No. 2 and under-dash fuse/relay box connector B (36P) terminal No. 29 [No. 20].

[ ]: Without HID

With HID





Without HID





Is there continuity?

YES -

Go to step 14.

NO -

Repair an open in the wire between the left headlight (high beam) and the under-dash fuse/ relay box.�

14. Check for continuity between each headlight (high beam) 2P connector terminal No. 1 and body ground.





Is there continuity?

YES -

Faulty MICU; replace the under-dash fuse/relay box.�

- USA models Under-Dash Fuse/Relay Box Removal And Installation (USA Models)
- Canada models Under-Dash Fuse/Relay Box Removal And Installation (Canada Models)

NO -

Repair an open in the BLK wire or poor ground (G201-right side, G401-left side).�