Polaris 155 800 Code 520335 5 - Your Complete Diagnostic & Fix-It

You’re geared up, miles from the trailhead, and the crisp air promises a perfect day of riding. Then, it happens. The dreaded check engine light flickers on, and your machine starts sputtering. You pull the code, and your dash flashes back at you: polaris 155 800 code 520335 5. That feeling in the pit of your stomach is one every rider knows and hates.

Don’t let a cryptic code cut your adventure short. Here at FatBoysOffroad, we believe in empowering you to understand and fix your own machine. We promise this guide will demystify that error code, turning confusion into confidence.

We’ll walk you through exactly what this code means, the common culprits behind it, and a step-by-step diagnostic process to get you back on the trail. You’ll learn how to pinpoint the problem, from a simple loose wire to a faulty component, saving you time and a hefty bill from the dealership.

What Exactly is Polaris Code 520335 5? Breaking Down the Numbers

At first glance, “520335 5” looks like a random string of numbers. But for a technician, it’s a specific message from your Polaris’s brain, the Engine Control Unit (ECU). Let’s translate it into plain English.

This code is made of two parts:

SPN 520335: This is the Suspect Parameter Number. It points directly to the Fuel Injector 1 (PTO/Mag Side) Driver Circuit. On most Polaris 800 snowmobiles, this is the injector on the left side of the engine as you sit on the seat—the side with the primary clutch.
FMI 5: This is the Failure Mode Identifier. An FMI of 5 means “Current Below Normal or Open Circuit.”

When you put them together, the polaris 155 800 code 520335 5 means the ECU has detected an electrical problem with the PTO-side fuel injector. It’s trying to send a signal to fire the injector, but it’s not getting the correct electrical response back. Think of it like a broken wire in a light switch; the power can’t get where it needs to go.

Common Symptoms & Causes of This Injector Fault

Your machine will almost certainly let you know something is wrong before you even pull the code. Understanding the symptoms can help confirm your diagnosis and get you started on the right track. This section is a crucial part of our polaris 155 800 code 520335 5 guide.

Telltale Signs Your Ride is Throwing This Code

Because a fuel injector isn’t working, your engine is essentially trying to run on only one of its two cylinders. You’ll likely experience one or more of these issues:

Check Engine Light (CEL): This is the most obvious sign. The ECU logs the fault and illuminates the light.
Rough Idle or Misfiring: The engine will sound and feel unbalanced, shaky, or like it’s “skipping” a beat.
Significant Loss of Power: Running on one cylinder cuts your engine’s power in half. It will feel sluggish and won’t rev up properly.
Hard Starting or No Start: The engine may struggle to turn over or fail to start at all, especially when cold.
Smell of Unburnt Fuel: You might notice a strong gasoline smell from the exhaust as raw fuel from the dead cylinder is pushed out.

The Usual Suspects: What Causes Code 520335 5?

The code points to an electrical fault, which narrows it down. Here are the most common problems with polaris 155 800 code 520335 5, from most to least likely:

Damaged Wiring Harness: This is the number one culprit. Wires can get chafed from rubbing against the frame or engine, melted by exhaust heat, or even chewed by rodents during storage.
Loose or Corroded Connector: The electrical plug on the fuel injector itself (or at the ECU) can become loose from vibration or contaminated with water and dirt, causing a poor connection.
Failed Fuel Injector: The injector is a small electronic solenoid. The tiny coil of wire inside it can break, creating an “open circuit” and triggering the code.
Faulty ECU: This is extremely rare, but it’s possible for the driver circuit inside the ECU to fail. Always rule out everything else before suspecting the ECU.

Your DIY Toolkit: Essential Gear for the Diagnosis

Before you dive in, gather the right tools. Trying to diagnose an electrical issue without the proper gear is like navigating without a map. You’ll just get lost and frustrated.

Here’s what you’ll need:

Basic Hand Tools: A good socket set, screwdrivers, and pliers will be necessary to access the engine components.
Digital Multimeter (DMM): This is your most important tool. You cannot properly diagnose this code without one. It allows you to measure resistance (ohms) and check for continuity.
Test Light or Noid Light: A noid light is a simple tool that plugs into the injector harness and flashes to show you if the ECU is sending a signal.
Electrical Contact Cleaner: A spray can of this will help you clean any grimy connectors without leaving a residue.
Dielectric Grease: Use this to protect your clean electrical connections from moisture and corrosion.
Service Manual: While not a tool, having the official service manual for your specific year and model is invaluable. It provides exact wiring diagrams and resistance specifications.

How to Diagnose and Fix Polaris 155 800 Code 520335 5: A Step-by-Step Guide

Alright, let’s get our hands dirty. Follow these steps methodically. Do not skip ahead! This process is designed to find the simplest problems first. This is the core of how to polaris 155 800 code 520335 5 diagnosis.

Step 1: Safety First & Visual Inspection
Before you do anything else, disconnect the negative terminal on your battery to prevent any accidental shorts. Safety is always priority one.
Now, with a good flashlight, perform a thorough visual inspection. Trace the wiring harness from the PTO-side fuel injector all the way back towards the ECU. Look for any obvious signs of damage: pinched wires, melted insulation, or areas where the loom has rubbed through against the chassis.
Step 2: Check the Injector Connector
Locate the electrical connector on the PTO-side injector. Carefully unplug it. Inspect both the male and female ends of the plug. Are the pins clean and straight? Do you see any green or white crusty corrosion?
Even if it looks clean, spray it with electrical contact cleaner and let it dry. Apply a small dab of dielectric grease to the seal and plug it back in. Make sure it clicks firmly into place. Sometimes, this simple step is all it takes.
Step 3: Test the Injector’s Resistance
This is where your multimeter comes in. Set it to measure resistance (Ω). Unplug the injector connector again and touch the two probes of your multimeter to the two metal pins on the fuel injector itself.

You should get a reading, typically between 12 and 15 ohms (check your service manual for the exact spec). If you get a reading of “OL” (Open Line) or 0, the internal coil of the injector is broken. The injector is bad and must be replaced.
Step 4: The Injector Swap Test (A Classic Pro Tip)
If the injector’s resistance tests good, the problem is likely in the wiring. A great way to confirm this is to swap the injectors. Unplug both the PTO and MAG side injectors, physically unbolt them, and swap their positions.
Reconnect everything and start the engine. If the code moves to the other side (e.g., you now get a code for Injector 2, like 520336), you’ve 100% confirmed the injector you moved is faulty. If the 520335 5 code returns, you know the injector is good and the problem is definitely in the PTO-side wiring or the ECU.
Step 5: Test the Wiring Harness
This is the most advanced step. With the injector and ECU unplugged, set your multimeter to the continuity setting (it usually has a beep function). Use your wiring diagram to identify the two wires for the PTO injector at the ECU plug.
Place one probe on a pin at the injector plug and the other on the corresponding pin at the ECU plug. The meter should beep, indicating a solid connection. If it doesn’t, that wire is broken somewhere in the harness. Test both wires. Also, test each wire to a chassis ground; it should not beep, as this would indicate a short circuit.

Polaris 155 800 Code 520335 5 Best Practices and Care Guide

An ounce of prevention is worth a pound of cure, especially when it comes to electrical issues. Following a few best practices can save you from future headaches and benefit your machine’s longevity.

Preventing Future Electrical Gremlins

The best polaris 155 800 code 520335 5 care guide is about proactive maintenance. During your regular post-ride checks, take a moment to look over your wiring harness. Ensure it’s properly secured with zip ties and not rubbing on any sharp edges or hot components.

Anytime you have electrical connectors apart, a small amount of dielectric grease is your best friend. It seals out the moisture that leads to corrosion and poor connections.

Sustainable and Eco-Friendly Repair Considerations

Thinking about a sustainable polaris 155 800 code 520335 5 repair might seem odd, but it’s about being a responsible rider. If you find a broken wire, take the time to properly solder and heat-shrink the repair instead of replacing the entire expensive harness. This reduces waste and saves you money.

Furthermore, fixing a misfiring engine promptly is an eco-friendly polaris 155 800 code 520335 5 practice. A properly running engine is more fuel-efficient and produces fewer harmful emissions. Always dispose of old parts and chemicals responsibly.

When to Put Down the Wrenches and Call a Pro

There’s no shame in knowing your limits. While this guide empowers you to do a lot, there are times when calling a certified technician is the smartest move.

Consider getting professional help if:

You’ve tested the injector and the wiring, and both check out. The issue may be the ECU, which requires specialized tools to diagnose and program.
You are not comfortable working with electrical systems or using a multimeter.
The wiring damage is extensive and located in a hard-to-reach place.

Guessing can lead to more damage. A good mechanic can pinpoint the issue quickly, saving you from replacing parts you don’t need.

Frequently Asked Questions About Polaris Code 520335 5

Can I still ride my Polaris with code 520335 5?

It is strongly not recommended. Running the engine on one cylinder can cause serious internal damage. Unburnt fuel can “wash” the oil from the cylinder walls, leading to scored pistons and costly engine failure.

How much does it cost to fix code 520335 5?

The cost varies wildly depending on the cause. A simple wiring repair might only cost you some time and a few cents in materials. A new OEM fuel injector can cost between $100 and $200. A shop diagnosis and repair will likely involve 1-3 hours of labor plus parts.

Is the PTO side always the left side on a Polaris 800?

Yes, on Polaris snowmobiles and most of their off-road vehicles, the Power Take-Off (PTO) side is the side with the drive clutch. When you are sitting in the driver’s seat, this is the left side of the machine.

Will just clearing the code fix the problem?

Absolutely not. Clearing the code only temporarily turns off the check engine light. The ECU continuously monitors the circuits, and as soon as you start the engine, it will detect the same fault and the code will immediately return.

Tackling a polaris 155 800 code 520335 5 can feel intimidating, but it’s a manageable job for a careful DIYer. By following a logical diagnostic path—inspecting the easy stuff first, testing components methodically, and confirming the failure before you buy parts—you can solve the problem and get back to what matters most.

Ride safe, wrench smart, and we’ll see you out there on the trails!

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Thomas Corle

Founder & Automobile expert at FatBoysOffroad

Automobile expert and off-road enthusiast, sharing in-depth knowledge of vehicles, gear, and adventures. Helping readers make smart decisions and enjoy the thrill of off-roading safely and confidently.