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View Full Version : ? Erroneous Trouble Codes



Hooaah
10-21-2012, 03:01 PM
Long Story. History of getting the flashing check engine light and going into spark skip mode when the engine shouldn't be that hot. This happened many times and there was never a trouble code. I'd read on another forum that some folks attributed this to voltage fluctuation in the fan "fooling" the ECM. I also heard the fan is always supplied with power and the ECM turns the fan on or off by supplying a path to ground ( or not). One rider solved this issue by disconnecting the fan from the factory connection and hard-wiring it to a toggle switch. So i tried this with a variation. I put a three position toggle switch in. Position 1 - all OEM connections electrically intact. Position 2. OEM power path intact, no ground. Position 3 - OEM power intact, ground to another grounding point - not back to the ECM. I did this to try and confirm the diagnosis and to let the fan work as designed unless there was trouble.. This worked for several months. Generally it would work well OEM, but it if started to spark-skip I switch to direct ground and it would run fine. All this time - no trouble codes.

Then it stopped working. I would get flashing engine light no matter what position. Checked fro trouble codes - 13, 16, 21, 34. Yikes. Yet the bike did not go into spark skip but ran well.

Thought I'd try one more variation and completely take the fan out of the EMC circuit. I left the female end of the coupler intact and cut the male end off. Except without the female end inserted, the check-engine light is always on. So........i inserted the unconnected male end into the female plug into the factory connection, No change. Tried connecting the ground end of the dead male connection to ground - no change. Positive wire to power. No change. Positive wire to ground. No change. Positive wire to ground wire (both on the dead male plug). Engine light goes off. Stayed off. Bike ran great. Until I turned it off hot and restarted it. Engine light back on. Disconnected then reconnected the dead plug. Light went off - then came back on. Stayed on. Checked the fan fuse - blown. Replaced it - light is off - though I haven't run it after that. Now obviously I'm no electrical genius, but my theory is everything was fine until the engine got hot. IT stayed fine when th bike was running but when I turned off the bike ( or restarted it), the read head temp sensor was hot enough that the ECM called for the fan, and since the positive lead that the ECM "thinks" is connected to the fan is now connected to the ground, it caused the fuse to pop.

By the way - no obvious cracks in the ECM or chafed wires.

Thanks for taking the time to read this saga - any suggestions

Hooaah
10-22-2012, 06:55 PM
wow. 25 views and no suggestions.

anrkizm95
10-22-2012, 07:25 PM
Checked fro trouble codes - 13, 16, 21, 34. Yikes. Yet the bike did not go into spark skip but ran well. last time i had that many codes it was a bad positive connection at the cable one of the wires came loose from the cable end.unless you triggered these codes during testing.