hey guys im hoping one of you can help me out with this I have an 08 848 with the above reoccurring fault resulting in the ECM light coming on. it doesn't matter if the bike is hot or cold and can come on at any time however its more likely to come on when the rev range is between 2800 and 3200 I've checked fuses and changed relays twice now and it still comes up, I know both fans work and come on below 106 degrees C at my wits end now someone please shed some light on what it could be..
The Power control module that monitors over current of the fan circuit is part of the ecu. If your sure the fans and relays and associated wiring are good, i would check the ecu connections for corrosion etc and if nothing found the problem could be the ecu itself. Generally Pcm's turn off the fan circuit above a certain speed (usually mid 30's) so that may explain the fact it only comes on at low revs as that corresponds to a lowish speed and the circuit being live.
Ah I get it, easier to monitor rev range than speed so I assume between X and Y revs the circuit is live ? That would explain why it behaves when I'm giving it some. Relays changed, ChrisW has kindly lent me an ECM but the fault still happens, I have a spare fan to try and I'll inspect the wiring for chafing .
Alongs those lines yes, it's live at over a certain temp (about 104 or something) or if the speed is lower than 38mph, with an overide of the speed cutoff if the temp exceeds a much higher critical temp. In which case they run constantly regardless of speed until the temp drops or you go up in flames. The ecu elimination is good news i guess so it would look like a short or high resistance in the circuit somewhere.
Sounds to me like something is drawing too much current. Most likely culprit is corroded connectors in the fan circuit, but it could be a fan motor on the way out as well. With the bike not running try spinning the fan by hand and see how it sounds/feels. If the bearings or brushes have failed it may explain the current draw.
Thanks guys, I'm going to do some testing today but it would be a real advantage to know what sort of resistance I should or shouldn't be looking for. At what point in the circuit do I look for anomalies ? Supply side or switch side? I.e before or after the relays ? Cheers
If you're measuring point-to-point for connectivity (ie, just checking wiring) then there should be zero resistance. You would need to check the workshop manual for the details of checking the fan itself and what resistance the motor windings should have.
The fans are turned on by a relay which is switched by the ECU. So the ECU doesn't electrically see the fans, only the relay. Could it not, more likely, be a faulty relay?
