[Edofthenorth]

I have a 2015 cforce 500 having problems. Will only start with full throttle won't gain any power will shut off when I let throttle go. Exhaust is white an spark plug is black.. This machine pisses me off. Sure would like some help

[NMKawierider]

Man that sounds like one that needs to go in to the shop asap.

[Edofthenorth]

That's the thing, I'm in remote Alaska an the cost for it to go to the shop alone is $1,500.

[NMKawierider]

Man...that's a bad situation. Hopefully some of the 500 guys will chime-in and give you a hand. I know there have been some issues with them... especially the first ones.

[Cosmosdan]

I am assuming that you have the regular 500 model. There should be a light blinking. By the sounds of it, it's an EFI problem. Just a rough guess is the TPS. Figure out what the blinking code is and we may be able to help more.

[Cosmosdan]

Also try the service manual. There is one here under this category. Not the one I posted, try the other one. That is for the efi models.

[Cosmosdan]

I know this sounds dumb, but have you checked the air filter or made sure critters haven't tried to nest in the airbox or exhaust? I have seen mice load up the inside of a machine pretty good.

[Edofthenorth]

Yup pull air intake off, had nothing but trouble since the beginning. The tranny sensor freaked out on me changed that. Wet clutch gave out on me changed that. Now this. What happen, was was running fine until all of a sudden no power as if the piston went out. Only way to get it started now is a full throttle am still no power as if piston is out. I check compression there is plenty. Changed plug it was caked In carbon as if getting too much fuel. Changed out fuel pump an injector an fuel filter. Still same crap.. Unplugged ecm for ten mins nothing. No lights or warnings on dash. Don't have a computer to hook up to it.. About to throw this Chinese force pos into the Bering sea

[viejoperro]

Sorry to hear that  , for your description and having change the injector and fuel pump, no warning light, I would check oxygen sensor, air temp intake sensor and water temp sensor, anyway without an error light is difficult to chase the malfunction, best would be with the PDA computer but since you are far away from a dealer?. My best guess since there is no malfunction on the ECU is that one of the sensor is sending wrong data to the ECU making it to put to much fuel in to the chamber. Have you tried to ground the ECU to see if an error code shows up?

Regards

[Edofthenorth]

Thanks for quick reply..
How do I go about grounding out the ecm? Also with the other sensors you mentioned would unplugging any of them give me a better chance of diagnosing the problem?

[viejoperro]

Since we don't have many choises, you have to go in a trail and error process, unplug a sensor one at the time and see if it makes any difference. Any sensor you unplug should give the ECU an error and the light should come on, blinking. To ground the  ECU you have to look for pin 26 on the Bosch M3.0 ECU, wich your atv should have? Since it is a 2015 look for a 3 wire plug labeled ECU and find the purple wire to ground it wich is the K line pin 26. If not you have to bypass pin 26. BE CAREFULL, you can blow the ECU. Do you have the service manual for more troubleshooting and to find the 26 pin?

Here is a video, unafortunatelly it is in spanish, it will give you an idea, if you need translation of a part let me now.

BE CARFULL, hope we can find the problem

[Edofthenorth]

Ok so I was able to get a hold of a computer should be here tomorrow on the bush flight. I might have to get back with u again to operate the thing if not we see how things go. Got the video an didn't understand a thing. Question, if I go unplugging sensors to test will I have to ground ecm?
Thanks

[viejoperro]

No, one this is to troubleshoot the sensors, and the other is to get the error codes from the ECU. With a PDA computer you test everything thru it, much better and safer. Find the PDA ECU test plug,

[Edofthenorth]

K I will get bk with u in a day or so thanks

[Cosmosdan]

viejoperro is spot on. Get the manual for the cf500-5B. Location of info as follows

1-19 location of test plug under seat
1-23 how to count the blinks
11-25 grounding of the data link, k line(ecu pin 26)
Info on the testing unit you have coming is after this section and farther down is the code list.

I think one of the sensors is working, but not giving the right data. I had a car that had a bad MAF sensor go out. I put in a brand new one and still ran bad. Turned out that the new one was giving bad data and the O2 sensor was telling me I was super lean. If the O2 sensor gives a code, it might just be doing it's job and don't call it faulty right away. You will most likely get at least one for it.


Service and users manual

https://drive.google.com/file/d/0B4YlLEIJfz2eM0V0OXBBTHM0S2c/view?usp=sharing