Polaris Ranger RZR 636 crank position sensor problems. Stalling out, dying when warm, CPS fixed.

I go through a Polaris Ranger 636 crank position sensor code what the problems are and what harnessed to look in. Hope it helps!

[@mechanicforlife9468]

Great video! thanks for posting it.

[@MrKingmanb]

Thank you kind sir. I like your methods.

[@charlespick248]

Wow!! Great video explain if 646 code and details. Again thanks

[@j.r.gordon9719]

dude this is one outstanding video thanks man for real

[@performance406]

Thanks, hope it helped

[@lxndrspnl8006]

Excelente! Gracias por compartir esto. Yo tengo un problema similar. Este video es de mucha ayuda.

[@jeremyc7836]

I just bought a 2019 scrambler 850. I drove it 3 hours, took a break and went back to ride and it wouldn't start. Took it to the dealer and they said crank position sensor is bad. Mechanic said they go bad sometimes. I hope I can get at least 6 hours out of the new sensor lol

[@performance406]

If it does it again, probably is the wiring

[@blueeyephil]

Thanks for your video. I'm chasing this issue myself. My issue is it starts find some days, but if it has rained or high humidity it will not. And I keep it in a building so it's not out in the rain. So far, I've changed the sensor no change. So I changed the fuel pump and it started and kicked off quicker even. But I had checked the pressure is it was ok, but I did the pump anyway. Worked for a week then it rained again. So it's not starting again. I've got new plugs and they are sparking. Of course I don't know if the are at the correct time or hot enough. I've started to work on the wiring and I'm not very comfortable with that. I started at the sensor and see a bare wire there. But it goes into insulation down by the plug and looks like there is a broken strand or two there. So wondering if it is probably that before going further into the wiring.

[@performance406]

Could be, the wiring on these only get worse with age.

[@timgile8144]

You used foil tape like used on air ducts ? Then wrap all three wires with tape or something to hold them together?

[@darriousparker1915]

So will that cause it to have no spark?

[@trevorshoemake1923]

4yrs later with a 21 turbo s had the same issue

[@brandonchavez5224]

Stalls when warm? Won’t start back up until the motor has cooled down? Thinkin I’m having this issue possibly in my 2020 turbo s…

[@hap9915]

Sir.. great video. Thanks for taking the time to explain in detail, but not overtalkin. I have a 2016. Hard start... Unless I use starting fluid. After it warms up, it starts perfectly every time. Sometimes if I crank and and crank the CPS code will come up. . But if I just spray starter fluid, whike cold, and start it up, no CPS code. Runs fine. A lot of videos mention adjusting valves, if it starts up once warm. Any thoughts from a guy who has dealt with these?

[@performance406]

Could be valves, but if they are that far out you'd probably be able to hear the rattle well when cold, not only that, as your valvetrain ages you usually get tighter tolerances as the valves wear into the head, not looser, and the symptoms would say the tolerances are so far out when cold it starts hard, but after warm up and expansion they are close enough to aid in starting OK again. Could also be fuel injectors, fuel pump, or even spark plugs. I' would still lean towards a bad wire somewhere , these have terrible harnesses. Start with the cheapest stuff first. Good Luck!

[@tammynoftsger6123]

I was just curious...we just bought a 2012 rzr polaris 800 and need to replace the cdi box....problem is, we don't know where it's located at. Could you please help?

[@johngould2288]

I bought a 2014 rzr 800s , a basket case. Rebuilt front diff fixed a wiring issue for the lights and winch. new rear side panels one rocker panel windshield and doors.it starts up great but when it warms up it starts to miss, stumble then die. I will check this out because no one seems to know whats wrong with it. thanks.

[@performance406]

Is it throwing a code? Check that.

[@johngould2288]

I think there was a code.. been busey fixing other stuff. vacation coming , going to Snake hunt in ok. your machine dose what mine is doing. gotta tare it back down to put new muffler on. want to get new shocks, whats you sugjest for $ and value, performance?

[@performance406]

@@johngould2288 You could go a hundred different ways on this. Really depends on budget and applications. For shocks, I usually recommend Fox. They offer some really good budget shocks, but the higher end , like the 2.0 RC Race shocks are really good, for higher speed control and dampening. If you want tuned shocks to your specific wants I strongly recommend Shock Therapy. www.shocktherapyst.com. Shoot them a message. As for exhaust I lean towards Big Gun, believe it or not, however, unless you are going very high performance just about any exhaust on the market will be suitable. My 2 cents. hope this helps, and have fun with the build. Check out all that wiring! Polaris builds a good machine, just wish they put a little more quality into the wiring. Hope this helps

[@bobbytaaniathibodeau6791]

I have a 2013 rzr 800s that is throwing the same code. Starts fine cold, runs fr 15-20 till it gets hot then sputters and dies. Wont start again till cooled off. How would heat play a factor with a kinked or unprotected wire?

[@performance406]

In that situation you might just want to start with the actual sensor any electronics as they warm up expand from the heat. This will in turn caused them to stop working if there are any broken or loose connections inside the sensor or on a circuit board. However this machine that is in this very video had those exact same symptoms. if it's a seven-year-old Polaris, you better dig into that wire harness in my opinion and look for any kinks or rubbed through wires. Thanks. I hope this helps. Good luck

[@performance406]

I guess I didn't even mention it, but if it's throwing the 636 code, it's somewhere between your crank position sensor and ECM. Good luck!

[@mattandkatchristie2552]

I fixed mine using this video but just used electric tape on the wire never had tinfoil tape and now mines backfiring at acceleration sometimes.

[@performance406]

Could possibly be another wire also. I do recommend using tin tape to help signal.

[@mattandkatchristie2552]

@@performance406 I took it all apart again taped wire then used tinfoil over the wire and taped again lol. Will see what happens!!! Thanks!!

[@charlespick248]

Explain what you mean by a whoop dedo from factory???

[@performance406]

Haha. I meant instead of a straight wire there is a 180 or 360 degree loop in it. Kind of like when you have and extension cord hanging and try to unravel it fast and it ties in knots instead of laying out straight.

[@vicvicki1]

I have a 2015 Polaris Rzr 1000 and when it's warmed up, it will stall in gear when I brake to stop. Could the Crank position speed sensor, be the problem?

[@performance406]

Yes, Very good chance of it, most complaints I've seen start with the warm engine comment. Could also be your stator or fuel pump, but probably not in my opinion. When things warm up they expand, if you have bad connection or wiring it can cause it to separate more and quit working. Usually why you see stators failing whenever only when engines warm up. Thanks, Hope this helps.

[@vicvicki1]

@@performance406 I appreciate the quick reply! I'm gonna try and order a replacement cable and I hope that fixes it. Just frustrated right now because I just upgraded to 30" Maxxis tire and got new KMC Rims, new PRP Suspension seats and I replaced the stock Springs with Eibach Stage 2 Springs and then this happens when I'm set to take out for a ride.... Smh.

[@justintaylor3030]

Hey man I’ve got a 2016 900xp ranger and I’m having issues with it cranking. It started out back a few months ago I got it out one day and it took me like 3 times of turning it over for it to crank and it kept doing that all throughout the day that day. The next weekend it wouldn’t crank at all. So since then I’ve replaced fuel pump, new spark plugs, and ignition coil. Currently waiting on fuel regulator to get here. But I’m not sure what to do next, it turns over strong, but just not firing. I have no codes or anything. Any feedback would be awesome!

[@performance406]

Good chance your stator has failed. Check for spark with a plug out while turning it over.

[@justintaylor3030]

@@performance406 thank you for getting back with me, I’ll definitely look into that next

[@justintaylor3030]

@@performance406 any recommendations on where to look for a stator?

[@performance406]

@@justintaylor3030 ebay

[@jamesc2010]

Having the same issue. But mine has shown CHK ENG code of 0 636 2 (CPS code). Started fine all this time, but we've had really cold weather and I didn't start it for a few days. Now just cranks and cranks and cranks. I'm assuming maybe bad gas although it's fairly fresh. Or something frozen or stuck? Let me know what you find out on yours.

[@waynemontgomery7805]

Have a 2016 xp4 1k and it is having a tough time. Will crank and crank but wont start unless i jiggle the wires just right. How far back up the harness have you seen a bad wire. I replaced the sensor and the connector and still have same issue. once i get it to start it runs perfect. Is there another sensor in that part of the harness that could cause this. The TMAP, Speed sensor, Shifter sensor, and whatever sensor in exhaust are all in the same harness at the rear of the machine.

[@performance406]

I'll bet you it's a broken wire in the harness very similar to the video. The one in the video was the farthest one I've ever seen it was almost at the seat. They can be a real pain. Look for a twisted wire like the video. Good luck.

[@waynemontgomery7805]

@@performance406 I stripped it back a few feet already and replaced a large portion of the two unshielded wires. When it first started I could flick the cps wire and get it to start now it's much more difficult. I will keep stripping back wire loom I guess. And retest the ground to the chassis and where it splits to the coil.

[@performance406]

@@waynemontgomery7805 They can be aggravating. Is it only showing one trouble code?

[@waynemontgomery7805]

@@performance406 it doesnt show any codes at all. Replaced plugs, coil, cps, cps connector. At first I could start it by flicking the connector now I really have to wiggle the harness to fire then runs great. Stripped back a lot of the harness but dont see anything crazy. Need to look over grounds again I guess and keep stripping wire loom back. Could so much shielding being removed be causing an issue?

[@performance406]

@@waynemontgomery7805 probably not. nine times out of 10 and I'll throw a code if it's not getting a signal from the crank position sensor or any sensor, for that matter. Be sure to look for damaged or kinked wires. If it is starting when you wiggle the harness, it should be in the harness somewhere. Check your fuel pump pressure also. Hope this helps, good luck.

[@shanderescalona5768]

I have the same problem but Whith an 2012 polaris 800 crew

[@performance406]

Probably the wiring harness off the CPS. The map sensor can trigger it too but that is more rare. They be a real pain to find. Good luck I hope this helps.

[@shanderescalona5768]

Am from Colombia What you recommend me to do

[@performance406]

Basically what the video goes over. They can be a real pain but if it the 636 code it's in that harness or the CPS itself.

[@thezemog123]

i change fuel pump and tps pigtails and tmap harness to tryna figure out why i cant use full throttle its starts at 4500 4800 rpm sounds like it’s hitting limiter u think i need a new computer starts and runs fine but just sucks cant i cant use full power

[@performance406]

I really don't know, depending on the year, make sure it isn't something simple like a bad reverse rpm limiter switch , or seatbelt speed limiter.

[@anthonycarothers5983]

What is the proper way to check the plug? I replaced the CPS sensor and didn’t fix problem. Bike died after staring up and running and now won’t start at all. 636 code

[@performance406]

There really isn't a good reliable way. Some will wiggle the wires, some will use a multi-meter to check for resistance, voltage, etc, but nothing works real well. That is one reason this can be such an elusive problem. Good luck

[@dickfacepeterson]

polaris has god awful cheap wiring