Polaris Code 65590: 5 Causes and How to Clear

Has your Polaris RZR thrown the pesky 65590 code, and you don’t know what could be the problem? Things can worsen if your UTV enters limp mode and bogs down while accelerating.

While this code is a nightmare to most drivers, it’s a great way to warn that the side-by-side has run into problems. So, what causes RZR code 65590, and how can you resolve the underlying issues?

Below we’ll discuss the causes of this diagnostic trouble code, including the Polaris Code 65590 fix.

What Is Polaris RZR Code 65590?

The code 65590 in your Polaris RZR UTV indicates a misfire when you run the engine. It’s a general code that doesn’t specify the affected cylinder. As the ECU throws this code, your UTV will go into limp mode to prevent damage to the engine.

A misfire in your Polaris occurs when there’s no proper ignition in one or more cylinders. Two other codes will accompany the Polaris code 65590. These are Polaris codes 65591 and 65592. The two misfire codes are specific as they indicate the problematic cylinders.

Polaris code 65591 indicates a misfire detected in cylinder 1 (the PTO side). On the other hand, Polaris code 65592 indicates a misfire detected in cylinder 2 (the MAG side).

Several reasons will cause your ECU to throw the 65590 RZR code. However, there’s one common reason when the code flashes on the dashboard. It occurs when the RPM ranges programmed in the UTV’s ECU fail to match the speed or throttle level.

When this happens, the ECU translates that the RPM levels are out of range. It, therefore, sends the misfire codes on the dashboard.

How to Clear the Polaris RZR Code 65590

If you’re driving and this code flashes on the dash, you might want to clear it. Doing so will give you time to reach home or a repair shop to resolve the underlying problems. Follow these steps to clear the diagnostic trouble code:

  • Stop the UTV and turn the engine off.
  • Allow the engine to sit for 25-30 minutes.
  • Turn the engine on. Doing this eliminates the limp mode. However, the fault code will remain on the dash.
  • Drive your UTV slowly for a few minutes to allow the ECU to clear the code.

If the UTV goes into limp mode and throws the code 65590 again, you’ll need to diagnose and fix the causes.

Polaris Code 65590 Fix

Let’s now examine the causes of code 65590 and effective fixes.

Slipping Drive Belt

One of the most common causes of the RZR code 65590 is the drive belt slipping. When the drive belt slips, the crankshaft rotates at an abnormally high speed. As a result, the RPMs go out of range and trigger this diagnostic trouble code.

But what causes the belt to slip? Typically, the drive belt will slip due to the following factors:

  • Worn-out or damaged belt
  • Missing belt clogs
  • Glazed belt

Effective Fixes:

Inspect the belt to determine if it’s the cause of misfires and Polaris code 65590. If there are any missing belt clogs, replace them. Replace the belt if it looks worn, burnt, or damaged.

If you have a glazed belt, the tensioner might be worn and needs replacing.

Ignition System Issues

The ignition system can cause your Polaris RZR UTV to misfire and throw the fault code 65590. Issues with the ignition system occur due to a faulty spark plug, ignition coil, ignition switch, and wiring.

A functional ignition system delivers a high-voltage spark to ignite the air-fuel mixture. If the spark plug, ignition coil, ignition switch, or wiring is faulty, it doesn’t ignite the air-fuel mixture in the combustion chamber. As a result, the engine might misfire and shut down.


Inspect the plug and replace it if fouled. Then, use a multimeter to test for resistance on the spark plug wires. If the reading is more than 8k ohms, replace the wires.

Test the ignition switch and coil and replace them if they’re defective.

Clutch Issues

A defective clutch is another suspect that might cause the Polaris code 65590 to appear on the dash. If the clutch malfunctions, it fails to engage or transfer power. This issue leads to the UTV misfiring and throwing the fault code.

If the clutch is the culprit, you should inspect for the following:

  • Loose spider nut
  • Dirt and grime buildup in the clutch system

Effective Fixes:

Locate the spider nut within the primary clutch and check if it’s loose or damaged. Tighten the nut if it’s loose, or replace it if worn or damaged.

After fixing the spider nuts, check if you have a properly torqued primary clutch. The loose or damaged nut can cause the primary clutch to get loose and spin on the crankshaft.

Dirt and grime might accumulate in the clutch system and cause the clutch to malfunction. Blow compressed air around the clutch components to remove dirt and grime. Then spray brake cleaner on the components to remove stubborn dirt and grime.

Fuel System Issues

The fuel system should feed the combustion chamber with sufficient fuel. If the engine doesn’t get the right amount of fuel, there’ll be an incorrect air-to-fuel mixture, resulting in misfires.

Issues with the fuel system occur due to the following:

  • Malfunctioning fuel pump
  • Clogged fuel injector
  • Dirty fuel filter
  • Blocked fuel lines

Effective Fixes:

Drain the fuel before considering any Polaris code 65590 fix related to the fuel system.

Then inspect the fuel lines to ensure no residue or debris blocks fuel flow. Blow compressed air to clean the buildup if there’s a blockage in the lines. Then remove the injector to clean any dirt or gunk. Soak it in an injector cleaner to remove all the clogs.

Next, test the fuel pump and replace it if it’s malfunctioning. You’ll also need to replace a dirty or damaged filter. 

Then fill the tank with fresh fuel. Lastly, add a fuel system cleaner in the tank and run the engine to clear any stubborn gunk along the lines.

Air Intake Issues

The air intake allows the engine to receive sufficient air for combustion. If the air intake is dirty or clogged, there’ll be insufficient air in the combustion chamber. As a result, your UTV engine will misfire and throw the RZR code 65590.


Check the air intake and the filter for dirt. If these components appear clogged, clean them. Replace these components if they look worn or damaged.

Faulty Throttle Position Sensor

The throttle position sensor (TPS) monitors the position of the throttle plate to ensure the engine receives the right amount of air. It communicates with the UTV’s ECU to control the flow of air and fuel into the engine.

If the TPS is defective, it sends incorrect information to the ECU. As a result, the engine receives an incorrect air-to-fuel mixture, leading to misfires.

Effective Fixes:

Locate the TPS and inspect for signs of wear or damage. You can also use a scan tool to retrieve codes indicating that the TPS is faulty. Remove the bolts and screws holding the TPS into place. Then replace it with a new TPS.

After replacing the defective TPS, use the scan tool to clear the fault codes.

Polaris code 65590 fix

Final Thoughts

The code 65590 flashing on your UTV’s dash can be annoying and distracting. This fault code indicates misfires in the engine. To find an effective Polaris code 65590 fix, you must know the cause of the misfires.

Issues such as a slipping drive belt, malfunctioning ignition system, faulty TPS, and clogged fuel system will cause these misfires. Address these issues to stop the misfires and clear the Polaris RZR code 65590. Stick to your UTV’s routine maintenance to prevent issues that might trigger misfires in the engine.