Fi light c-28 code gen 2 issue

Jenko89

Jenko89

Registered
Hi can anyone help a few weeks ago mid ride I have a 09 gen2 owned for 4 years with no problems, I randomly got a fi light appear so upon turning back I turned the bike off by the ignition and wouldn’t start again as battery was dead.
I’ve replaced the battery with a lithium one which was recommended to me and I’m still getting the same issue on the 2nd time riding after I thought it was the battery being the problem the fi light appeared again mid ride about 10 minutes down the road I got home (with no difference in performance) and kept engine running and flipped into dealership mode which displays a -c28 code
but if I leave the bike to idle on the side stand no fault code appear but the battery still dies.
I’ve done a basic check of the voltage when the bike is ideling and all seems ok and again when revved to 5k and there is juice going back into the battery.
ive checked the Haynes manual and it’s saying secondary throttle valve actuator but from what a few garages have told me I should be getting a (limp mode) effect which I’m not.....
Is there something else I’m missing ?
Any help would be greatly appreciated
 
Hi @hayawakend yeah I’ve got a gen 2 Haynes service manual and have read it along with the fi codes but the effects of the issues mines displays aint there which is why I’m struggling to work out what the issue is also being told a garage will charge me £1900.00 for a new throttle body plus actuator is quite upsetting to say the least since there don’t seem to be a issue with the throttle body’s.
I’ve also been told lithium battery’s are really bad for busas is this true ?

Also a garage told me they could dyno my busa and flash the ecu to fix this problem but I was told if I flashed a ecu if ever the busa had to go in for repairs anywhere they could refuse because the ecu has been flashed
 
Jenko89 said:
also being told a garage will charge me £1900.00 for a new throttle body plus actuator is quite upsetting to say the least since there don’t seem to be a issue with the throttle body’s.
Click to expand...
Agreed.

Jenko89 said:
I’ve also been told lithium battery’s are really bad for busas is this true ?
Click to expand...
No. Categorically false. MANY members here run lith batts with zero issues. I'm one of them, have had a lith in for ... a year now??

Jenko89 said:
a garage told me they could dyno my busa and flash the ecu to fix this problem but I was told if I flashed a ecu if ever the busa had to go in for repairs anywhere they could refuse because the ecu has been flashed
Click to expand...
Not really. There might be some shops that don't want to get in to the ECU, edited or not - that's understandable - but depending where you live/ride, I'd hazard there will always be another shop that will be willing to work on the bike and its (modded) ECU.

My question becomes what are the fixes this tuner proposes to make to the ECU to solve your problem. Chances are someone here on this forum will have a much deeper understanding of your situation. Wait for some responses here before going with an ECU tune as a categorical remedy. Dyno runs aren't cheap but usually worth the $. And if you do plan a dyno, do your research as to what else you might want to accomplish afterwards. Exhaust modifications, for instance, generally are enhanced though (and even require) a dyno run. Dyno tuning is a bit of an information rabbit hole, if you know what I mean, but worth the time & effort.
 
HayaWakened said:
Agreed.


No. Categorically false. MANY members here run lith batts with zero issues. I'm one of them, have had a lith in for ... a year now??


Not really. There might be some shops that don't want to get in to the ECU, edited or not - that's understandable - but depending where you live/ride, I'd hazard there will always be another shop that will be willing to work on the bike and its (modded) ECU.

My question becomes what are the fixes this tuner proposes to make to the ECU to solve your problem. Chances are someone here on this forum will have a much deeper understanding of your situation. Wait for some responses here before going with an ECU tune as a categorical remedy. Dyno runs aren't cheap but usually worth the $. And if you do plan a dyno, do your research as to what else you might want to accomplish afterwards. Exhaust modifications, for instance, generally are enhanced though (and even require) a dyno run. Dyno tuning is a bit of an information rabbit hole, if you know what I mean, but worth the time & effort.
Click to expand...
Yeah I did ring up a shop who do dynos and ecu flashes aswel as repairs and he did recommend this was the way to go as he would dyno it first then flash the ecu and delete the stva issue then redyno and put a custom map on for £400 but since I’ve never had a ecu flash and the moment he said he would delete the information from it that’s where I got worried if it’s the correct thing to do or not
 
Sounds to be to be a charging issue, the rectifier might have bit the bullet.

You will need to check the out put of the alternator to the rectifier to the battery...the manual will direct you on this.

Anytime a new battery is drained the culprit is the charging system.
 
Bumblebee said:
Sounds to be to be a charging issue, the rectifier might have bit the bullet.

You will need to check the out put of the alternator to the rectifier to the battery...the manual will direct you on this.

Anytime a new battery is drained the culprit is the charging system.
Click to expand...
As my learned friend from the frozen wasteland known as Canada has said correctly, the first place to look is the charging system output, at the 3 stator phases ( 80V AC at 5000rpm) and also the reg/rectifier voltage output to the battery. (13.8 - 14.5V DC)
A low battery voltage will do exactly as you described, bring up a c28 code, low voltage to the secondary throttle valve actuator. It will also prevent the starter motor from cranking and the ECU will have too low a voltage to operate the ignition system and the fuel system.
Good luck.
Kiwi :thumbsup:
 
Kiwi Rider said:
As my learned friend from the frozen wasteland known as Canada has said correctly, the first place to look is the charging system output, at the 3 stator phases ( 80V AC at 5000rpm) and also the reg/rectifier voltage output to the battery. (13.8 - 14.5V DC)
A low battery voltage will do exactly as you described, bring up a c28 code, low voltage to the secondary throttle valve actuator. It will also prevent the starter motor from cranking and the ECU will have too low a voltage to operate the ignition system and the fuel system.
Good luck.
Kiwi :thumbsup:
Click to expand...

Uh, it's 90'F here today.....so things are thawing nicely...my igloo is melting though.
 
Thanks so much for your advise everyone I have the chance at buying a new regulator rectifier but not sure on the connections for the 09 gen 2 as seen many with one plug and others with 2 plugs I did do a voltage test on the old battery to try and eliminate the issue is there any particular reason why the reg or altanator might have died at all ?
 
Jenko89 said:
Thanks so much for your advise everyone I have the chance at buying a new regulator rectifier but not sure on the connections for the 09 gen 2 as seen many with one plug and others with 2 plugs I did do a voltage test on the old battery to try and eliminate the issue is there any particular reason why the reg or altanator might have died at all ?
Click to expand...
The earlier gen 2s were known for these failures...there was a recall and maybe your bike didn't get taken in for it.
 
Jenko89 said:
Thanks so much for your advise everyone I have the chance at buying a new regulator rectifier but not sure on the connections for the 09 gen 2 as seen many with one plug and others with 2 plugs I did do a voltage test on the old battery to try and eliminate the issue is there any particular reason why the reg or altanator might have died at all ?
Click to expand...
Your '09 Gen 2 (USA model?) should have 2 plugs on the reg/rectifier.
You could visually check it on the bike to be certain.
Glad to be able to help,
Any technical questions we are happy to help with.
 
Kiwi Rider said:
Your '09 Gen 2 (USA model?) should have 2 plugs on the reg/rectifier.
You could visually check it on the bike to be certain.
Glad to be able to help,
Any technical questions we are happy to help with.
Click to expand...
Uk model mins is mate but yes going to see if I can follow the wiring to the plugs
 
Ive had the c28 issue also, but no battery or charging issues. My problem ended up being the secondary throttle position sensor was stripped out. Something to check if charging system ends up being in spec.
 
Jenko89 said:
I contacted Suzuki and they clarified it was done 3 years ago the month before I bought it so I’ll be looking for a new regulator aswel as new generator
Click to expand...

Make sure they are the fault before going to spend your hard-earned money.

@JaimeW has some input as well-check that sensor first to rule it out.
 
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