DTC B1280: Turn Signal Switch Circuit Malfunction

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. 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 ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Operate the turn signal switch in left and right positions.
Check for DTCs with the HDS.
Is DTC B1280 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.
Select LIGHTING from the BODY ELECTRICAL system select menu, then enter the DATE LIST.

Check each combination light switch position value with the DATA LIST menu.

When the turn signal switch is in left position:

DATA LIST

Data List	Value
Turn Signal Switch (LEFT)	ON
Turn Signal Switch (RIGHT)	OFF

When the turn signal switch is in right position:

DATA LIST

Data List	Value
Turn Signal Switch (LEFT)	OFF
Turn Signal Switch (RIGHT)	ON

Are all data list values correct?

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

USA models (see REMOVAL AND INSTALLATION ).
Canada models (see CANADA MODELS ).

NO -Go to step 7.

Turn the ignition switch to LOCK (0).
Disconnect the combination light switch 12P connector.
Turn the ignition switch to ON (II).
Select the BODY ELECTRICAL system select menu, then enter the LIGHTING SYSTEM.

Check each combination light switch position value with the DATA LIST menu.

DATA LIST

Data List	Value
Turn Signal Switch (LEFT)	OFF
Turn Signal Switch (RIGHT)	OFF

Are both data list values indicated OFF?

YES -Go to step 15.

NO -Go to step 12.

Turn the ignition switch to LOCK (0).
Disconnect under-dash fuse/relay box connector M (34P).
Check for continuity between body ground and under-dash fuse/relay box connector M (34P) terminals No. 2 and No. 6 individually.

Fig 1: Checking Continuity Between Body Ground And Under-Dash Fuse/Relay Box Connector M (34P) Terminals No. 2 And No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Faulty MICU; replace the under-dash fuse/relay box.
- USA models (see REMOVAL AND INSTALLATION ).
- Canada models (see CANADA MODELS ).
Turn the ignition switch to LOCK (0).
Do the combination light switch test (see COMBINATION LIGHT SWITCH TEST/REPLACEMENT ).
Is the combination light switch OK?

YES -Go to step 17.

NO -Replace the combination light switch.
Disconnect under-dash fuse/relay box connector M (34P).
Check for continuity between under-dash fuse/relay box connector M (34P) terminals No. 2, No. 6 and No. 33 and combination light switch 12P connector terminals No. 2, No. 1, and No. 12.

Fig 2: Checking Continuity Between Under-Dash Fuse/Relay Box Connector M (34P) Terminals No. 2, No. 6 And No. 33 And Combination Light Switch 12P Connector Terminals No. 2, No. 1, And No. 12
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 19.

NO -Repair an open in the wire.
Check for continuity between under-dash fuse/relay box connector M (34P) terminals No. 2 and No. 33, and between connector (34P) terminals No. 6 and No. 33 individually.

Fig 3: Checking Continuity Between Under-Dash Fuse/Relay Box Connector M (34P) Terminals No. 2 And Between Connector (34P) Terminals No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the wires.

NO -Faulty MICU; replace the under-dash fuse/relay box.
- USA models (see REMOVAL AND INSTALLATION ).
- Canada models (see CANADA MODELS ).