got a 00 929rr and i bought it wrecked. guy i got it from said its a bad ecu so i got one and put it in same problem. got another and same problem. i am a car and diesel truck mechanic so i figured i could figure a bike out. i have traced it down to the ecu is not sending a ground to the fuel pump relay to kick it on( i can jump a ground to it and it does run so i know the pump is good) and the ecu is not sending a ground to the coils to spark them. i have a service manual for the bike and have done all the tests in the book but i dont see how 3 ecus for a bike only made for 2 years have the EXACT problem. someone help me please. you can text me if you have a good idea. 1-828-275-6889 thanks
Ron

 

I agree with you on the ECU after a few, but have you done a continuity check between the plug of the ECU and the ground wire on the fuel pump/coil packs? Maybe you have a cut in between the wiring. Dont see how all the ECU's are bad especially with the exact same problem through all of them. Start by checking your wiring harness....

 

Something to check, seeing as throwing ECUs at it sound fishy to me as well, is the ground itself. While the ECU does ground the injectors to fire them, the fuel pump is grounded permanently, not through the ECU. It could be possible that the bad ground causing the fuel pump to not come on is also the ground that feeds the injector portion of the ECU. I would speculate that the ECU is trying to fire the injectors, but when it connects there is no ground on the other end to pass on to each injector. I can look up the ground pins to the ECU tomorrow if you have trouble downloading the wiring diagram. I printed it poster size and traced important circuits with colored highlighters, it's been very handy. Hope you figure things out soon.

 

thanks guys but i pulled the entire harness off and pulled the loom off and looked at each wire individually no bad spots anywhere and a good connection on all the sensors. the fuel pump ground is in the relay not the pump. there are 4 wires going to the relay one ground straight from the ecu to turn kick the relay on. the ecu is not giving the ground to turn the relay on. i can ground it and it runs.(the pump that is)

 

I had almost this exact problem. I finally found out that a - wire in the ecu connector had corroded on the inside. Couldn't see any signs of it outwardly, started retracing/isolating wires, bypassed that - wire w/ a new 1, everything worked. Ended up getting an old ecu harness, removed the faulty wire & pin from ecu conn. & replaced it and a good length of the wire. That was 17k ago & not a problem since. Try isolating & grounding ecu -'s, if u get a good grd to bad 1 everything will work. process of elim.

 

If you have the fuel pumps ground going to the relay that is not how the bike is supposed to be wired and somebody has messed with it. The Green wire from the pump is the ground wire. It should go direct to ground and the coolant temperature switch for the fan. The Brown/Black wire is the fuel level sensor wire, and the Brown wire is +12V from the fuel pump relay. The two Black/White wires going to the relay are +12V, one to feed the Brown output when the relay is energized, and the other to energize the relay when the ECU gives it a ground through the Brown/Black wire. If I understand correctly, your pump runs when you touch the Brown/Black wire from the relay to ground?

 

yes it runs when i put a ground to the relay. all the wiring is good nothing has been messed with. its also throwing a faulty ecu code. any one know where i can get one.

 

I think that the issues could be a wire that is corroded possibly at a connector. If you had the loom off the bike this check can go very eazy. As Pimpin said a continuity check should be done on all wires, once you rule out that, check the fuel pump relay for solid voltage, typically if you can force the pump to run with jumpers , your relay is not working. Ive not seen an ECU go out on these bikes, (tho im sure it happens) dont give up , it sounds like you have the skill to dig in. Also check the bank angle sensor as if the bike was wrecked , these are the systems that shuts down ... good luck bro

 

Don't rule out the possibility that there is a wiring problem that is frying any good ECU you put in. I would start going to local bike meets and hand someone a cash deposit to try the ECU off of their running bike.

 

I know this is an old thread and the situation has probably been resolved but this is a common problem and I want to let everyone know what the solution is. There is a diode in the stock ignition that drops the voltage from the 12volts to somewhere between 4-9 volts. So if you put a 1k, 1 watt resistor from radio shack in place of that diode(in between the positive wire and the pink wire) this will drop the voltage to the desired level. You can check by making sure the voltage coming out of the resistor and leading to the pink ignition wire is around 4-9 volts with a multimeter. As soon as you do this you should be able to hear the fuel pump prime for the desired 2 seconds. And all other issues aside the bike should start.