Honda HR-V: DTC B1279 Dimmer Switch Circuit Malfunction

DTC (MICU)

NOTE : If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks.

1. Exterior lights system check 1:

1. With the headlight dimmer switch in the neutral position, check the parameter(s) below with the HDS.

Is either information indicator ON?

YES

Go to step 4.

NO

Go to step 2.

2. Exterior lights system check 2:

1. With the headlight dimmer switch in the high beam position, check the parameter(s) below with the HDS.

Are both information indicators ON?

YES

Go to step 3.

NO

Intermittent failure, the system is OK at this time.

3. Shorted wire check (H/L HI SW to PASSING SW line):

1.  Turn the vehicle to the OFF (LOCK) mode.
2.  Disconnect the following connector.

Combination light switch 12P connector

3. Connect terminals A and B with a jumper wire.

4. Turn the vehicle to the ON mode.
5. Check the parameter(s) below with the HDS.

Are both information indicators ON?

YES

Repair a short between the wires.

NO

The H/L HI SW to PASSING SW wire is OK. Replace the combination light switch.

4. Determine possible failure area (combination light switch, others):

1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connector.

Combination light switch 12P connector

3. Turn the vehicle to the ON mode.
4. Check the parameter(s) below with the HDS.

Is either information indicator ON?

YES

Go to step 5.

NO

Replace the combination light switch.

5. Shorted wire check (PASSING SW, H/L HI SW lines):

1. Turn the vehicle to the OFF (LOCK) mode.
2. Disconnect the following connector.

Under-dash fuse/relay box connector B (20P)

3. Check for continuity between test points 1 and 2 individually.

Are there continuity?

YES

Repair a short to ground in the wire.

NO

The PASSING SW and H/L HI SW wires are OK. Faulty MICU; replace the under-dash fuse/relay box .

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