Seeing a fault code display on your Polaris UTV is always worrisome, but especially when that code is accompanied by your vehicle going into limp mode.
That has been the experience for the many owners who have come across Polaris code 65590 flashing up on their dash while out for a drive.
Polaris code 65590 is a misfire code that is usually accompanied by Polaris code 65591 and/or Polaris code 65592 as they all go hand-in-hand.
Code 65590 occurs most often in the Polaris Ranger 1000, Ranger XP 900, Ranger 570 and RZR 1000 models but are not limited to these.
If you’re experiencing any of these fault codes, the following questions are likely running through your head:
- What do these codes mean?
- How serious are they?
- What caused them?
- Can I keep driving while they’re on?
- How do I fix and get rid of them?
- How do I know if my UTV is okay?
This guide will answer these questions and assist you in overcoming these pesky fault codes.
Table of Contents show
Polaris Code 65590 Meaning
Code Description: Misfire Detected Cylinder Not Identified
Polaris code 65590 references a random misfire somewhere in your UTV. This is the most common code riders will see.
Polaris Code 65591 Meaning
Code Description: 65591 Misfire Detected Cylinder 1 (PTO)
Polaris code 65591 references a misfire within the PTO side of your engine, which is the Power Take Off where the crankshaft and clutch transmit power to the driveshaft.
Polaris Code 65592 Meaning
Code Description: 65592 Misfire Detected Cylinder 2 (MAG)
Polaris code 65592 references a misfire within the MAG side of your engine, which is the Magneto side where electricity is generated for the ignition system.
Why Do These Polaris Misfire Codes Occur?
There are a number of different potential causes for these misfire codes, but there is one common theme when they occur.
This theme is the RPM ranges programmed into the Electronic Control Unit.
When the correct RPM levels do not match up with a certain speed or throttle level, this signals to the ECU that the RPMs are out of range and it sends one or more misfire codes as a result.
So what can cause a fluctuation in RPMs?
- Belt slipping
- Clutch issues
- Clutch system modifications
- Gear reduction
- Tire sizes changed
And until the RPMs are back in range, these misfire codes will continue to happen.
What Happens When These Codes Occur?
A misfire code will almost always be accompanied by the vehicle going into limp mode and bogging down so that it cannot reach a speed greater than around 35 mph.
The overwhelming majority of the time, the existence of one of these codes means there is an issue with your vehicle.
But there have been rare instances documented where the codes have displayed in error and have gone away shortly thereafter.
Polaris Code 65590 Fix
If experiencing a misfire code along with your vehicle going into limp mode, you’ll need to stop your vehicle and shut it off.
After letting it sit for thirty seconds or so, turning it back on should eliminate limp mode but the codes may remain on your dash.
To eliminate the codes from displaying, you’ll need to slowly drive the vehicle until the Electronic Control Unit no longer senses any faults and clears the code.
This can take anywhere from thirty seconds to thirty minutes of driving and beyond. And if your ECU still senses faults, the issue will continue.
If The Codes Remain Or Limp Mode Returns
If your vehicle quickly goes into limp mode again after restarting it, you most likely have a serious issue.
Likewise, if just the misfire codes remain and will not go away, this is also a sign there may be a serious issue.
In either case, you’ll need to inspect your vehicle for some of the common causes in order to permanently fix this.
MORE: Polaris Ranger 1000 Problems
Common Causes Of Misfire Codes
As highlighted earlier, there are a number of things that can throw the RPMs out of whack.
If you’ve made modifications to your vehicle’s clutch system, gearing, or tires and are experiencing misfire codes, you may just need to have your ECU tuned so that the correct RPM levels are recalculated and applied.
Gilomen Innovations created tuning with these specific fault codes in mind and their tunes are highly recommended for eliminating this misfiring issue.
But for those who have not made modifications, these codes likely signal a more serious underlying issue and are probably due to one of the following:
- Belt-related misfires
- Clutch-related misfires
- Ignition-related misfires
- Valve-related misfires
- Fuel-related misfires
Let’s explore how to identify and overcome these issues.
Belt-Related Misfires
The drive belt is the most common cause of a misfire code. A belt-related misfire can be caused by any of the following:
- Belt slipping
- Missing belt cogs
- Belt hourglassing
- Belt burns
- Belt glazing
A slipping belt will cause the crankshaft to rotate at a higher speed than expected and the RPMs to jump, which will trigger these misfire codes.
When seeing a misfire code, you should start with inspecting your belt for any of the above. Any missing belt cogs, hourglassing, burns, or glazing will likely result in the belt slipping.
If your belt is in bad shape or exhibits signs of any of these types of damage, your belt is the most likely cause of your problem and a new belt may very well solve it.
However, it is important to remember that a damaged belt is usually the sign of a problem elsewhere, with the belt being the victim of this.
So while replacing the belt may solve your issue temporarily, you may continue to experience belt damage and ensuing misfire codes until the underlying issue is fixed.
MORE: Polaris Ranger XP 900 Problems
Clutch-Related Misfires
If your belt is burnt up or exhibits any damage outside of general wear, the main suspect should be the clutch system. Clutch-related misfires and belt issues are usually caused by the following:
- Failed spyder rollers
- Improperly torqued primary clutch
- Dirty clutch system
The spyder rollers are prone to failure in the stock clutches in Polaris utility vehicles, which can lead to belt damage from the belt rubbing against one or both sides of the clutch.
This is a common issue and will simply damage a new belt in due time, so the spyder rollers and clutch system should be inspected before replacing the belt.
You should also inspect the torquing of the primary clutch to ensure it is not loose and spinning on the crankshaft.
Lastly, grit and grime will build up in clutches no matter how or where owners drive their Polaris vehicles.
Blowing out the primary and secondary clutches may help solve your issue, and should be done around every 300 miles of riding regardless.
Ignition-Related Misfires
Ignition related misfires are rare but do still occur, and can be caused by the following:
- Spark plugs
- Spark plug wires
- Faulty fuel injector
- Faulty fuel pump
If your spark plugs are the issue, you’ll likely know it as you should feel an actual misfire take place in the engine when starting your machine. That said, the spark plugs can cause these codes.
Inspect them for spark plug fouling and replace them if necessary. You can also test the spark plug wires to ensure they are reading at 8K OHMS or less.
You can also inspect the fuel injector and fuel pump to ensure these are not causing a misfire.
Test the fuel injector by pulling the injector out and ensuring the spray pattern is that of a fine mist and not a stream.
The fuel pump can be tested by removing the hose and turning on the ignition to ensure fuel sprays out as it should.
Valve-Related Misfires
An issue with your valves can also cause these misfire codes, though this is less common.
To confirm, you’ll want to test the compression in both cylinders. You’re in good shape if the compression is between 150 and 180 lbs and is close to equal in both cylinders.
If your cylinders have more than a 10% difference in compression, your valve clearances are likely off due to tightening or loosening of the valves and should be checked and adjusted to the proper clearances.
Fuel-Related Misfires
Water in the fuel tank can also cause a misfire when sucked into the fuel pump.
Using any ethanol-based fuel will increase the potential for water to accumulate in the fuel tank and make this an issue.
But for owners who use their utility vehicles on the regular, this shouldn’t be an issue as water accumulation in the fuel tank generally occurs when fuel in the tank sits for a month or longer.
Conclusion
At the end of the day, these three Polaris fault codes usually signify an underlying issue with your vehicle.
While the most common cause is a faulty drive belt, it is recommended to inspect the clutch, valves, and components of the ignition system and fuel system to be sure you fix the issue long-term.
Before you go, check out the following articles for more on Polaris utility vehicles:
- Polaris Ranger 1000 Problems
- Polaris RZR 200 Top Speed
