Yesterday I gave my 2004.5 Sportsman 500 HO a good bath with the garden hose. This morning the battery was dead. Connected the jumper box and the cooling fan started immediately. If I turn the key switch to ON, the display shows ENGINE HOT, even though the engine has not run for more than 18 hours. Apparently, the fan came on sometime in the night and drained the battery. Based on my perusal of this site and others, I suspect this is the often mentioned ECM issue. This did happen once before, at that time I merely disconnected the battery, waited a few minutes, reconnected and the problem went away. No such luck this time. Starting with the simple tests, 2 questions: I checked the thermo sensor, it shows 1370 ohms at about 90 degrees, is this correct? I assume it is a thermistor. If the ECM is the issue due to moisture, is it likely that the problem will resolve itself when dry or is the ECM most likely toast? Thanks in advance.

 

Room temperature the thermistor should show around 37.3 k ohms. At 212 degrees it should drop to 1.2 k ohms. You can try to blow out the connections on the ecm,but if it doesn't help then it probably needs replacement.Could have shorted it out. These were problem years on all ecms and draining batteries,not charging,erratic fan operation were some of the symptoms.Your machine may or may not fall under the recall,but even if the ecm has been replaced,replacement can do the same.Huge ATV Recall by Polaris - Sportsman and Scrambler

 

Thanks for the reply. I believe the replacement ECM is part number 2203348. Is that correct? Based on photos this part number is a kit with wiring harnesses. Thanks again.

 

Yes this the correct part number.

 

Replaced the ECM, problem solved. Thanks for all your help.

 

The ecm is a unlimited time safety recall. I hope you did not pay for it?

 

The ECM recall does not apply to all machines, only certain VIN code ranges. Unfortunately, my machine was not one of the recalled units. And yes, I confirmed this directly with Polaris. So yes, I did pay for it. Thanks for your concern.

 

Sorry about that! Had some of the same problems on ones that weren't "officially" on the recall list,but Polaris knew about em.. Some(depending on the engineers) did warranty a few of these for me. Main thing is that if it happened within a reasonable time frame when the original bulletin came out on the ones NOT in the vin# range they were a little more "flexible" Now if a machine is not in the vin# range Or has been replaced once under the recall,they wont pay for a second one if it went out like they did for a us for awhile.Found this out from the guys at the shop..