DTC B1078, B1079: Daytime Running Lights Circuit Malfunction (Canada); Daytime Running Lights Circuit Malfunction (USA)

WARNING: This page is about a different car, the 2013 Honda Fit, 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Turn the ignition switch to ON (II).
Pull the parking brake lever.
Clear the DTCs with the HDS.
Release the parking brake lever.
Turn the ignition switch to LOCK (0), and then back to ON (II).
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.
Turn the headlight switch ON (high beam).
Do both headlights (high beam) come on?

YES - Go to step 8.

NO - Go to step 11.
Turn the ignition switch to LOCK (0).
Measure the voltage between body ground and under-dash fuse/relay box connector M (34P) terminal No. 16, and between body ground and under-dash fuse/relay box connector Q (16P) terminal No. 9.
Is there less than 0.1 V?

YES - Go to step 10.

NO - Repair open in the wire or poor ground (G501, G502).

Fig 1: Measuring Voltage Between Body Ground & Under-Dash Fuse/Relay Box Connector M (34P) Terminal 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Measuring Voltage Between Body Ground & Under-Dash Fuse/Relay Box Connector Q (16P) Terminal 9
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the voltage between body ground and under-dash fuse/relay box connector K (10P) terminal No. 10, and body ground and under-dash fuse/relay box connector N (8P) terminal No. 2.
Is there less than 0.1 V?

YES - Faulty MICU; replace the under-dash fuse/relay box:
- For USA models (see USA MODELS )
- For Canada models (see CANADA MODELS )
NO - Repair open in the wire or poor ground (G501, G502).

Fig 3: Measuring Voltage Between Body Ground & Under-Dash Fuse/Relay Box Connector K (10P) Terminal 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: Measuring Voltage Between Body Ground & Under-Dash Fuse/Relay Box Connector N (8P) Terminal 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to LOCK (0) and turn the headlight switch OFF.
Check the No. 28 (20A), No. 48 (10A) and No. 51 (10A) fuses in the under-dash fuse/relay box.
Are all fuses OK?

YES - Go to step 13.

NO - Replace the blown fuse and recheck. If the No. 28 (20 A) fuse is blown again, replace the under-dash fuse/relay box. If the No. 48 (10 A) or No. 51 (10 A) fuse is blown again, repair a short in the wire between the under-dash fuse/relay box and appropriate headlight (high beam).
Check the headlight bulbs.
Are the headlight bulbs OK?

YES - Go to step 14.

NO - Replace the faulty bulb and recheck.
Disconnect under-dash fuse/relay box connectors A (36P) and B (36P).
Disconnect both of the headlight 3P connectors.
Check for continuity between the right headlight 3P connector terminal No. 3 and under-dash fuse/relay box connector A (36P) terminal No. 30.
Is there continuity?

YES - Go to step 17.

NO - Repair open in the wire between the right headlight (high beam) and the under-dash fuse/relay box.

Fig 5: Checking Continuity Between Right Headlight 3P & Under-Dash Fuse/Relay Box Connector A (36P) Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between the left headlight 3P connector terminal No. 3 and under-dash fuse/relay box connector B (36P) terminal No. 13.
Is there continuity?

YES - Go to step 18.

NO - Repair open in the wire between the left headlight (high beam) and the under-dash fuse/relay box.

Fig 6: Checking Continuity Between Left Headlight 3P & Under-Dash Fuse/Relay Box Connector B (36P) Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between each headlight 3P connector terminal No. 2 and body ground.
Is there continuity?

YES - Faulty MICU; replace the under-dash fuse/relay box:
- For USA models (see USA MODELS )
- For Canada models (see CANADA MODELS )
NO - Repair open in the BLK wire or poor ground (G201-right side, G301-left side).

Fig 7: Checking Continuity Between Each Headlight 3P Connector Terminal 2 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.