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Electrical Nightmare 07 Gsxr 1000

2659 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.
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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 by the ECM to produce that signal.
Have you unplugged the ECM connectors and confirmed that there isn't any corrosion inside?
^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.
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.
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.
"ecu buring hot to the touch" is obviously not good.
My biggest concern is that there's a short somewhere. You could disconnect the battery, unplug the ECM, and go through the various pins looking for something with very low resistance. You can check the various grounds, then the leads to the coils and injectors, then the R instrument power, then the leads to the fan & fuel pump relays, etc. etc. It may seem like a lot but you ought to be able to work through them fairly quickly. The various coil resistances ought to be in the service manual. The relay coils are nominally 100 ohms. It wouldn't hurt to unplug the various components so that you're just looking for shorts to ground in the harness leads.

Our fuses are made by Japanese manufacturer Pacific and, at least back in the K5-K8 era, didn't have those nifty contacts for measuring the voltage drop across the fuses. I tried downloading the Power Probe table about 17 times without success. Here's an alternate table but the current vs voltage drop values seem to be different and I can't comment on that any further right now. I measure parasitic drain the way Suzuki shows in the service manual.

P.S. I stand corrected. I checked my K6 fuses. Though they're rather small, the fuses do indeed have test points where the voltage and voltage drop can be measured. All this time I've been touching the blades with my probe. The test points should be mentioned in the service manual.
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The correct relay cover is less than $5 so there's no reason to not have one. Check the battery cable routing vs the service manual pics and drawings as it should be well clear of the tank edges. You definitely don't want it shorting to ground there.
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