C40 code...

expat1970

Registered
last weekend i had the FI light come on , so i went home and got the code out of it (C40) went through manual idle speed control valve.so i performed the circuit tests from ECM to connector-ok . then tested valve had 79ohmes on each pair of terminals-ok manual says approx 80ohmes. it had a bit of corbon in bore so i cleaned it out and brass plunger on valve. reinstalled everything and went for a ride. light back on. i can get light to come on when i do a hard 3rd gear roll on through remaining gears.
did some searching and found out a clutch switch can cause this code to come on. i have a set of chinese levers on bike so i swapped out clutch lever back to stock and did another test ride, light still came back on :banghead: the only test i couldnt do was idle up/down as i dont have the sds(think that is what its called) to command idle up/down to see if valve can be commanded.
any insight from others are deff welcome.thinking about starting with a new clutch switch way cheaper than the ISC valve(321.00)
 
also if i just ride and be gentle with throttle the light still comes on it just takes longer to pop on
 
No help here, but I had the same C40 code pop up on my Gen II but that came from bypassing the clutch switch,once I reverted it back to where clutch switch is active my code went away. ???
 
disconnected pcV today, light still came on :( .ordered a clutch switch today,it was 23.00.cheaper to start there. if that doesnt fix it ill have to take to shop :banghead:
 
great news, once i picked up new clutch switch and looked at it i knew that was the prob. installed new switch and went for a hard ride trying to get light to come on but all stayed good :D here is a pic comparing old/new switch, you can see contacts stuck together. never seen one before so i didnt know they were suppose to be apart
IMG_0900.jpg
 
Cheap yes pia to find lol. The manual says nothing about a faulty clutch switch can cause this. Guess I need to get a Suzuki crystal ball lol
 
Cheap yes pia to find lol. The manual says nothing about a faulty clutch switch can cause this. Guess I need to get a Suzuki crystal ball lol

Mine did the same. I just played with the connectors a little and they loosened back up. Saved me from having to by a new switch
 
great news, once i picked up new clutch switch and looked at it i knew that was the prob. installed new switch and went for a hard ride trying to get light to come on but all stayed good :D here is a pic comparing old/new switch, you can see contacts stuck together. never seen one before so i didnt know they were suppose to be apart
View attachment 1549954
Ya mine is doing the Same thing. I'll look at that when I get home. So where did you end up finding one at?
 
He haven’t been on sight in 6 years wouldn’t expect a reply. If you click on the name you can see when they last visited.
Well I thank you all for all you insite. It's my first bike so wasn't really sure what I should be able to get out of it. Expresly considering I did all the work myself. Wasn't sure if I'd f**** something up or not. But it runs like a screaming machine so I'm happy. Just have to figure out the C40 code problem and make sure everything else is good then paint it and then it's complete.
 
Well I thank you all for all you insite. It's my first bike so wasn't really sure what I should be able to get out of it. Expresly considering I did all the work myself. Wasn't sure if I'd f**** something up or not. But it runs like a screaming machine so I'm happy. Just have to figure out the C40 code problem and make sure everything else is good then paint it and then it's complete.
Hope someone way smarter than me can help but try search de alot of thing about c40 code
 
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