Trying to fix this on my daughters Ciivic coupe LX 2011. Have checked the bulbs and all are OK. Manual doesn't show a fuse for turn signals but have checked #10 for Hazards and replaced it even though it is good. Also checked #23 as the diagram the Honda dealer gave me shows that as protecting the Hazard and Turn Signal lights. Both are in the Under hood fuse box.
The dealer suggested replacing the whole interior fuse box saying that the relay is part of that. That seems extreme to me and I'm not ready to do that. I wanted to check the Hazard switch/relay on the dash but I'm not sure how to check continuity once I get it out. Does anyone have a diagram for this or can you suggest something else to do before replacing the interior fuse box as this seems extreme?
Thanks

 

The hazard button switch is only a switch, not a relay. The audio unit would be removed to access the connector. Even without testing the switch itself, if you use a small paper clip or wire to jump terminal cavity no. 1 to no. 2, that would complete the circuit as if the switch was pressed. It is unlikely the cause of both turn signals and hazards not working.

The turn signal/hazard flasher relay circuit is part of the multiplex integrated control unit (MICU), built into the under-dash fuse/relay box. If there is no issue with the fuses, wiring, or bulbs, it may be the MICU. Due to the Immobilizer System, replacement of the under-dash fuse/relay box (MICU) will require programming.

 

Thank you for your prompt reply with suggestions and the diagram of the Hazard Switch. As mentioned my owners manual shows fuse #10 in the under hood fuse box as the one for the Hazards but the diagram the dealer gave me shows fuse #23 as the one for the "Turn Signal and Hazard Warning Lights" and says it should be "hot at all times". I took the fuse out and checked for voltage with car ignition on and there is no voltage. Can you explain the discrepancy between the #23 and #10 fuses? Since there is no voltage at #23 is that an indication of where the trouble is?

The parts dept at the local Honda dealer advised me to buy the interior fuse box (MICU) from a used parts dealer and try replacing it. It sounds like I'd get myself in trouble by doing so as it has to be programmed. Is this right and does that have to be done by a dealer. He also suggested I have the service dept diagnose the problem.

Any advice? Thanks so much for your help.

 

Under-hood Fuse No. 23 is the voltage back-up fuse for many circuits, including the MICU. It would be very unusual if there was no power there at the fuse box. Are you sure you're checking the correct fuse no. 23? Power to that fuse is fed from the large multi-fuse no. 1.

You can also test if power is going through the fuse with the fuse inserted. There are small contact points on the small fuse.

 

In regards to the MICU, many independent shops have the hardware/software and some locksmiths to do the programming.

 

I didn't realize you can make contact on the top of the fuse but I had a look and I'll need to get a small set of tips to make contact. I'll check again. I assume the ignition needs to be on all the way but the engine doesn't need to run, does it?

If there is no voltage on #23 can I try jumpering it to the positive side of the battery?

 

I checked #23 with my voltmeter and it has 12 volts.

Hazard lights work independently from the turn signals. Since most functions from the MICU box are working I'm beginning to think the problem is in that unit. Is that likely?