Suzuki SV650 Riders Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Never used a forum before so I hope you guys can help me out.. can’t find anything anywhere on this problem..

Bought a 2007 sv650 from a guy, battery was disconnected didnt think anything of it, he told me it wasnt running..

When the battery is connected the fuel pump starts to prime, even with no key in the ignition, whenI turn the bike to on with the killswitch off the fuel pump continues to prime, but when I switch the killswitch to run the fuel pump stops priming and the bike will turn over but not start. The fuel pump fuses and relays are fine. Maybe a killswitch? Ecu? Fi light is on with the code C41. Please help.
 

·
Super Moderator
Joined
·
9,148 Posts
C41 is the fuel pump relay circuit error code.

Several things can cause C41 but it is possible the ECM is bad (fried fuel pump relay control transistor) and the previous owner did some "creative wiring" to make the Run/Stop switch control the fuel pump relay directly.

Wiring the fuel pump like that would get the bike running without having to replace the ECM but is a hack way to fix things.

Pop the seat off, check to see if there are any wiring mods at the fuel pump wires or at the fuel pump relay.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
@TeeRiver thanks for the help, I was looking earlier and didn’t see any funky wiring.. When I get home
I’ll post some pictures here and see if you see anything.. I’m new to working on these but I figure it’d be noticable if there were some rigged wiring..
 

·
Super Moderator
Joined
·
9,148 Posts
If the wiring has been modified it should be easy to find. If not that, then this is an unusual problem.

Either way, the fuel pump circuit is straight forward so should not be hard to find the problem.

It is always an adventure buying a non-running bike. :D
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
I don’t see anything off… So from here, would I assume ecu/ecm.. I don’t think it’s the fuel pump since it does come on. The relay clicks but maybe it’s still bad. I assumed the killswitch maybe at first but since it still happens with the key off i’m doubting that.. let me know what you think please
 

Attachments

·
Super Moderator
Joined
·
9,148 Posts
If the fuel pump is running even with the key in the Off position, measure the voltage on Yellow/Black at the fuel pump relay. It is counterintuitive but 0v on Y/B turns the relay On, 12v turns the relay Off. Y/B comes directly from the ECM and is the fuel pump control signal.

When checking voltage, leave the fuel pump relay connected to the harness. Back-probe the connector to make contact (touch your meter lead to the contact from the back of the connector).

If Y/B is 0v, unplug the ECM and test again. If unplugging the ECM stops the fuel pump from running then the ECM had an internal short and needs to be replaced. If the fuel pump still runs even with the ECM disconnect then there is a short on Y/B to ground (intentional or accidental).

Please let us know what you find as this is an unusual problem and SVRider members are insanely curious. : -)
Rectangle Gesture Font Line Window
 

·
Super Moderator
Joined
·
9,148 Posts
Thanks. Definitely let us know how you make out. I've never seen the SV650 ECM fail in this mode, but the test is conclusive.

Usually, C41 results from a failed ECM fuel pump control transistor (open circuit) which causes the fuel pump never to turn on. However, this time it appears the transistor went short-circuit, fuel pump On even with the key off.
 
1 - 8 of 8 Posts
Top