Dreaded error 34

[MrC]

Hi all .new member here...and first time posting ..have found so much info on this site ...so can't thank everyone enough..only posting this to advise what issues I've had..the dreaded error 34 on. Fz6 NHG S2 ,2009 model...70k miles...for 6 months been having the 34 error...intermittently to begin .until was constant ,running in cylinders 1 & 4..unusable
Coils replaced...new switchgear .left and right..all connections checked..cleaned..every sensor removed and checked..every single one within spec.still same error..switched coil 1&4 with 2&3..didn't move to error 33 as suspected if coil issue...My loom is now 15 years old..and looking bit sorry for itself...rebuilt it completely..same issue..so bought new one from Yamaha ( from YOSHIPARTS...half price of usual UK suppliers)..same issue!.. finally got new ECU from YOSHI again..50% cheaper again...installed..and I'm good to go...error gone...£1000 later..and the 2nd hand 24k mile engine..and I'll be good for another 50k miles....only posting for others who have had this issue...I spent months trying to fix this as didn't wanna fork out too much for new parts...moral of the story....2nd hand parts..ECU...coils etc may fix this ..didn't for me though..sometimes new parts are the only way..

 

[Motogiro]

Congratulations on finally getting your bike running right and welcome to our great forum!
Actually you can get more money just selling the parts on your bike than selling your bike whole. Of course that works the same way when you need to buys parts.
If the issue had been discovered via standard testing process, it may have been more economical than throwing new or used parts at the problem.
One of the benefits of belonging to this forum is that even if you didn't get the technical input you needed on an issue you might receive the benefit of collective member's experiences.
Switching transistor failure is the most common failure requiring ECU replacement. Because coils can be intermittent regarding high tension secondary arc over, they are often harder to trouble shoot. Once you have total failure with a coil, it's a lot easier to find the culprit.
I would have suggested establishing continuity in the harness wire to the offending coil first before replacing the harness.
We even had a member on this forum dig out the potting on a bad ECU and replace the bad switching transistor!