B1078
DTC B1078: Daytime Running Lights Signal ErrorNOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.
Before troubleshooting, check the No. 3 (10 A) and No. 5 (10 A) fuses in the under-hood fuse/relay box, and headlight bulbs.
1. Clear the DTCs with the HDS.
2. Turn the ignition switch OFF, and then back ON (II).
3. Press the parking brake pedal.
4. Check for DTCs with the HDS.
Is DTC B1078 indicated?
YES - Go to step 5.
NO - Intermittent failure. The daytime running lights system is OK at this time. Check for loose or poor connections.
5. Turn the headlights (high beam) ON.
Do both headlights come on?
YES - Go to step 6.
NO - Go to step 9.
6. Turn the headlight switch OFF.
7. Select LIGHTING SYSTEM from the HDS, and enter the DATA LIST.
8. Check the ON/OFF information of the DRL Command in the DATA LIST.
Is the information indicator ON?
YES - Check the BLU/WHT wire between under-hood fuse/relay box connector H (18P) No. 10 terminal and the daytime running lights relay for an open/short. If OK, replace the daytime running lights relay.
NO - Go to relay control module input test. Relay Control Module Input Test
9. Check for continuity between the No. 3 terminal of the headlight 3P connectors and the No. 7 (right headlight) or No. 8 (left headlight) terminals of the under-hood fuse/relay box connector H (18P).
Is there continuity?
YES - Go to step 10.
NO - Repair an open in the wire.
10. Check for continuity between the No. 2 terminal of the left headlight 3P connector and body ground.
Is there continuity?
YES - Faulty relay control module; replace the under-hood fuse/relay box.
NO - Check the daytime running lights relay (left headlight only). If the relay is OK, repair an open in the wire or poor ground (G301 left side or G401 right side).