Civic Turn Signal Relays

echoparkpanda

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i recently installed some JDM ASTAR LED turn signals and now my turn signals hyper flash (emergency lights flash normally). I was told by some other people that changing the light relay could fix it. I would prefer not to splice wires or add resistors. Looking for a relay that will resolve the LED Hyperflash.
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zroger73

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There is no "turn signal relay" in most newer vehicles. Instead, the turn signals are controlled by what Honda calls the MICU (multiplex integrated control unit). In GM and some other makes, it's called the BCM (body control module). Sometimes the flasher sound is generated electronically and sometimes it is generated by the relay that activates the turn signal lights, but the rate at which the relay flashes is controlled by a computer.
 
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Newflyer3

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They haven't used relays in Hondas since 2005....
 

Acey

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You have no choice but to install resistance of some sort, or buy quality bulbs that include them inline and might not even require splicing.
 

Priceless_Civic

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i recently installed some JDM ASTAR LED turn signals and now my turn signals hyper flash (emergency lights flash normally). I was told by some other people that changing the light relay could fix it. I would prefer not to splice wires or add resistors. Looking for a relay that will resolve the LED Hyperflash.
Go with something like this:
http://www.jdmastar.com/product/216/7440-50W-6Ohm-LED-Load-Resistors-Set-of-2.html
I bought some for my hatchback so I wouldn't have to splice any wires. I only had to do minor trimming on the JDM bulb connector so that it would twist and lock into the factory housing.
 


Acey

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I guess there's no way to do this without resistors? You know... for power saving.
There'd be an extremely complex way involving some hack of the MICU that would not be worth it under any conceivable circumstsance. If it's power savings you seek, swapping both the front and rear to LED and adding only one set of resistors would still net savings, as would changing all other bulbs on the car to LED as nothing else would require resistance.
 

zroger73

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Power = power whether or not it produces visible light. A typical, 28-watt, 12-volt incandescent bulb has a resistance of about 5.1 ohms. The MICU is expecting to see about 4.6 amps of current for two turn signal bulbs. If the actual current draw is less than 4.6 amps by a preprogrammed value, the signal flashes at 2x the normal rate.

It might be possible to "hack" the MICU with the right knowledge and programming tools (likely not - or at least not practically), but it's much easier and cheaper to add resistors to prevent the rate increase if one is hellbent on retrofitting to LEDs. A resistor of the appropriate value so that the MICU still senses the same current as if an incandescent bulb were installed will still result in the same power consumption.
 

ChrisSi

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Power = power whether or not it produces visible light. A typical, 28-watt, 12-volt incandescent bulb has a resistance of about 5.1 ohms. The MICU is expecting to see about 4.6 amps of current for two turn signal bulbs. If the actual current draw is less than 4.6 amps by a preprogrammed value, the signal flashes at 2x the normal rate.

It might be possible to "hack" the MICU with the right knowledge and programming tools (likely not - or at least not practically), but it's much easier and cheaper to add resistors to prevent the rate increase if one is hellbent on retrofitting to LEDs. A resistor of the appropriate value so that the MICU still senses the same current as if an incandescent bulb were installed will still result in the same power consumption.
Not to mention, regardless of the light bulb's actual constant state power consumption, the turn signals aren't on all that long anyway unless you have your hazards on. Even then, what is it, a 50% duty cycle?
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