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Electrical Nightmare 07 Gsxr 1000

2661 Views 22 Replies 5 Participants Last post by  susanmario918
Hey y’all, unfortunately I am back again. I was involved in a motorcycle accident back in August of last year, and since then I have fixed everything (or thought I had fixed) that was broken in the wreck. A couple weeks ago, I really wanted to ride so I put my extra set of fairings on, then cranked the bike up. After it had warmed up, I sat on the bike and not even 2 seconds later it just shut off. I had the dreaded “chec” on the dash with the kill switch in the on position. I know from past experiences that this means the ecu isn’t communicating with the bike’s systems. I checked my kickstand switch and the jumper wire has continuity so I know it is fine. The wiring on my clutch switch wasn’t looking good so I replaced the whole left side switch assembly (Left handle bar). The wiring that ran from my kill switch looked like it had been burned through from the radiator, so I replaced the kill switch. I noticed that my ignition fuse had blown so I replaced it. I then checked my regulator/rectifier and noticed that the wires were burnt and the plugs.. Since my ignition fuse was blown, could my regulator have sent to much power to my ecu before blowing the fuse? I’ve checked my starter relay, switched fan with FP relay to no avail. I’ve done a visual inspection of my ecu and everything looks ok to the naked eye. I know I am basically just throwing parts at this bike at this point.. if this ecu is bad, this will be the 3rd ecu that has gone out. Is there a way to check to see if the ecu is bad? Still getting “chec” with kill switch on. Oh, and I’ve checked the side stand relay and it is working.!blinkers work and neutral light is on. @BillV would you mind helping me out?
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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.
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?
Any idea what could be going on? Ecu fried?
This 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.
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 replies
What code is showing in dealer mode ?
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.
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Have you unplugged the ECM connectors and confirmed that there isn't any corrosion inside?
Yeah that was one of the first things I did. The connectors looked perfectly fine. I replaced the wire harness recently too.
^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.
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.
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.
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.
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.
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.
Update. My new ECU arrived, and the bike is running great! Before installing the new ecu, I carefully checked the wiring harness. The starter relay was under the seat, and there was no protective covering on it. I fashioned my own protective cover out of plastic, and secured it around the relay with electrical tape. I noticed that the plastic sleeve protecting the positive lead on the relay was frayed from rubbing on the edge of my tank. I replaced the lead, and the plastic covering and made sure it wouldn’t rub on the tank. I replaced all fuses including the main 30amp fuses in the starter relay. Since this problem initially occurred I’ve replaced the regulator/rectifier (OEM), clutch switch, and kill switch. The only thing I can think of that may have caused this was my old regulator over charging my battery, then over charging the ecu. That in conjunction with the starter relay grounding out. What do you think? I’ve checked for continuity on the wires running from the tail end of the harness, to the connectors and everything checks out. So strange. Anyway, thanks for all your help @BillV and everyone else too. I greatly appreciate y’all.
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