Zenner diode bypass on budget
Actually I still have it on to this day, the only problem is when it gets cold the voltage drops, other than that fires right up every time and
runs like it should
runs like it should
Don't hold me responsible with something don't work right, but I swear on my mother's last breath it worked for me. And it was hooked up exactly as you see in the picture. I'm thinking that the 3.7 volts dropped the 12 volts down to nine ish. I tried the 9-volt battery trick but it never worked for me. Just make sure that you zap the batteries with the nickel plated strips, solder will not hold or stay. Good luck buddy
So much easier to just use factory design. Two blobs of solder and you’re DONE! Factory OEM configuration. Worked on millions of CBRs for decades!
WHY it doesn’t work is because you’re following idiot YouTube videos and other “guides” that has you installing zener diode BACKWARDS!! I’ve Googled searched and went through at least 100 of them. ALL WRONG AND BACKWARDS!!! EEEeidiots can’t even take simple photo with their camera to document Honda’s engineering work before tearing sh|t apart to try and “fix” it. Honda’s engineers (real EE) are way, way more qualified than any of those punk hacks.
Here’s background on zener diodes and how they work: https://www.circuitbread.com/tutoria...w-does-it-work
Sources for zender diodes, spend the whole $1.00 and buy 10x of them because you’re gonna destroy couple of them installing backwards and overheating them trying to remove. If you think a little for yourself and learn how zener diodes work, you can fix this properly first time around for $0.10 in less than 5-min!
https://www.digikey.com/en/products/...228BTR/1992219
https://www.elexp.com/products/111n7...s-vol-3-9-watt
https://store.synthrotek.com/39V-Zener-Diode_p_877.html
https://juriedengineering.com/produc...ng-temperature
https://www.circuitspecialists.com/1n4730a $0.05/ea !!!
Oh yeah, use one of these and confirm you’ve got 9v at ECU’s pink wire, otherwise you’ve installed zener diode backwards!!!
https://www.harborfreight.com/7-func...ter-63759.html
If it reads (battery voltage)-0.7v instead of (battery voltage)-3.9v, you’ve installed zener diode backwards!!! At least you’ll know why it didn’t work instead of just being puzzled and scratching your head…
BTW, there’s also tonne of possible problems besides zener diode that can cause no fuel pump prime, no sparks, no fuel and not start:
- battery too low (gee golly, how would you check for that?)
- main fuse or top-secret hidden FI fuse busted (but “Looks OK!”)
- kill-switch
- clutch switch
- neutral switch (even though light is green, broken wire to ECU)
- kickstand switch
- engine-stop relay
- fuel-pump relay
- fuel pump
- fuel pressure regulator
- fuel filtre
- injectors
- ignition coils
- crank/cam pickup-coils
- ECU
- corroded or broken wires or connectors in harness (culprit in 99% of cases)
all can keep bike from starting. Luckily, you can find exact problem with multimeter and not waste time & money shotgunning entire pile of parts above at bike hoping & wishing that’s last part you have to buy and bike still won’t start.
I’ve fixed this exact no pump-prime, no start problem for 100s of people in 5-min or less. Most of them in dark remote parking-lots in middle of night by phone! Many of them in pouring rain!!!
WHY it doesn’t work is because you’re following idiot YouTube videos and other “guides” that has you installing zener diode BACKWARDS!! I’ve Googled searched and went through at least 100 of them. ALL WRONG AND BACKWARDS!!! EEEeidiots can’t even take simple photo with their camera to document Honda’s engineering work before tearing sh|t apart to try and “fix” it. Honda’s engineers (real EE) are way, way more qualified than any of those punk hacks.
Here’s background on zener diodes and how they work: https://www.circuitbread.com/tutoria...w-does-it-work
Sources for zender diodes, spend the whole $1.00 and buy 10x of them because you’re gonna destroy couple of them installing backwards and overheating them trying to remove. If you think a little for yourself and learn how zener diodes work, you can fix this properly first time around for $0.10 in less than 5-min!

https://www.digikey.com/en/products/...228BTR/1992219
https://www.elexp.com/products/111n7...s-vol-3-9-watt
https://store.synthrotek.com/39V-Zener-Diode_p_877.html
https://juriedengineering.com/produc...ng-temperature
https://www.circuitspecialists.com/1n4730a $0.05/ea !!!
Oh yeah, use one of these and confirm you’ve got 9v at ECU’s pink wire, otherwise you’ve installed zener diode backwards!!!
https://www.harborfreight.com/7-func...ter-63759.html
If it reads (battery voltage)-0.7v instead of (battery voltage)-3.9v, you’ve installed zener diode backwards!!! At least you’ll know why it didn’t work instead of just being puzzled and scratching your head…
BTW, there’s also tonne of possible problems besides zener diode that can cause no fuel pump prime, no sparks, no fuel and not start:
- battery too low (gee golly, how would you check for that?)
- main fuse or top-secret hidden FI fuse busted (but “Looks OK!”)
- kill-switch
- clutch switch
- neutral switch (even though light is green, broken wire to ECU)
- kickstand switch
- engine-stop relay
- fuel-pump relay
- fuel pump
- fuel pressure regulator
- fuel filtre
- injectors
- ignition coils
- crank/cam pickup-coils
- ECU
- corroded or broken wires or connectors in harness (culprit in 99% of cases)
all can keep bike from starting. Luckily, you can find exact problem with multimeter and not waste time & money shotgunning entire pile of parts above at bike hoping & wishing that’s last part you have to buy and bike still won’t start.
I’ve fixed this exact no pump-prime, no start problem for 100s of people in 5-min or less. Most of them in dark remote parking-lots in middle of night by phone! Many of them in pouring rain!!!
Last edited by dannoxyz; Jan 14, 2024 at 08:14 PM.
Somebody give me a straight answer as to how to bypass this hiss bull**** cause everyone of you have given a different answer and honestly tried everything even hardwire the fuel pump with a switch and still nothing
You can't bypass HISS - it's a security feature. You need a key transponder paired to your ECU for it to work. The zener diode fix is completely different - that's for non-HISS bikes.
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