Hey Bill, sorry I forgot to mention that my fuel pump is not priming. I’ve checked the pump though, and it is working when 12v is applied directly. I’ve checked the O/W wire at the dealer mode terminal, and it’s reading 12v. Weird thing is, when I check the red wire out of the SAP connector, I’m only getting just above 1 volt. The bike was running fine until I sat on it. So maybe my seat hit the wiring harness or damaged the ecu somehow?Measure the voltage at the O/W lead to the dealer mode connector when the ignition is on. It should be at battery voltage. If it passes, measure the voltage on the R lead to the nearby SAP connector (8 pins). It should be 5 volts. Do you hear the fuel pump priming?
Based on what you've said, I'm suspicious of additional faults in the wiring harness.
Yea I’m thinking that it has to be that the ecu is fried. My regulator was burnt to hell and the wires had melted through the insulation. Plus the bike had been stuck in the rain after the accident. Maybe that is it. Idk. Thanks for the prompt and educated repliesThis doesn't look good for the ECM. First measure the voltage at the R/Bl lead to the fuel pump relay. It should always be 12 V. If it's OK you need to rig up some needles so you can measure things at the ECM connectors. You should be able to find the O/W, R/Bl, and R leads there. Measure them with the ignition on. The R is 5 V output to power the sensors so something's wrong with the ECM if it's getting power and not producing that signal. It doesn't take any fancy computing to produce that signal.
No codes are shown since the ecu isn’t communicating with the dash. It constantly shows “chec” as if the kill switch is in the off position, even though it is in the run position.What code is showing in dealer mode ?
Yeah that was one of the first things I did. The connectors looked perfectly fine. I replaced the wire harness recently too.Have you unplugged the ECM connectors and confirmed that there isn't any corrosion inside?
Bill, just a moment ago I turned the key on with the kill switch in the run position, and it still says “chec” but the radiator fan turned on. That’s super weird right? I haven’t unplugged or messed with anything other than changing the blown 10amp ignition fuse. I also noticed that my battery was almost completely drained.^Or the ECM is dead, which seems to be where this is going. It does seem strange that the bike was running until he sat on it. At the moment, that seems more like a coincidence as the ECM and its connectors should be far enough below the seat to not be affected. Not being able to produce the 5 V sensors power signal is a big deal to me.
The harness is definitely hooked up correctly. It was running completely fine before I sat on the bike. I put in a new regulator/rectifier and a new kill switch, but there’s really only one way to to install that. I did try switching the fan/fuel pump relays, but I put them back after the test. If the fan is turning on when I turn the kill switch on, but no fuel pump prime, no stv actuation, and “chec” is on the dash, does that mean the there is some sort of signal coming from the ecu? I did order a used ecu off eBay, but I’m scared that I will fry another one.Are you sure that you have things hooked up correctly? The fuel pump and the fan are located controlled by identical relays that sit next to each other. The relays are in turn controlled by the ECM. All bets are off if you don't have the harness installed correctly.
So I just went down to my garage and turned the key to see what happened, and the fan cut on with “chec” still in dash, and the ecu was burning hot to the touch. I unplugged it, and made sure none of the harness side connections were burnt. Visually they look fine. This ecu has got to be fried. What could have caused this? I’ve searched high and low using key words in the search bar, and have yet to find anyone with a similar symptom. I hope i don’t fry my next ecu just by plugging it in. I’ve double checked every connector and have cleaned with contact cleaner. Idk how to diagnose or fix this.If the wiring is correct, the only way for the fan to turn on is if the ECM pulls the G/R lead to the fan relay low. This is very similar to what happens with the fuel pump except there it's the Y/B lead. You could monitor them at the relay connectors to confirm that it's happening.
