There’s nothing like hitting the trail on your Polaris Sportsman 850 XP, but seeing a check engine light and the dreaded code 651 4 can stop the fun in its tracks. Suddenly, your power steering might feel heavy and unresponsive, and wrestling the bars feels like a workout you didn’t sign up for.
You’ve come to the right place. Here at FatBoysOffroad, we believe in empowering riders like you to handle their own maintenance. A diagnostic code doesn’t have to mean an expensive trip to the dealer. This comprehensive guide will walk you through exactly what the polaris 850 xp code 651 4 means and how to diagnose it safely, step-by-step.
We’ll cover the common causes, the tools you’ll need, a detailed troubleshooting process, and how to know when it’s time to call in a pro. Let’s get that power steering working and get you back on the trail where you belong.
What Exactly is Polaris 850 XP Code 651 4?
When your Polaris dashboard flashes a code, it’s speaking a specific language. Think of it as your machine’s way of telling you precisely where it hurts. The code 651 4 isn’t just a random number; it’s a very specific fault message.
The full diagnostic trouble code (DTC) is SPN 651, FMI 4. Let’s break that down:
- SPN 651: This points directly to the Electronic Power Steering (EPS) Control Unit. This is the computer module, or “brain,” that controls your power steering.
- FMI 4: This indicates the specific fault type, which is “Voltage Below Normal.”
In plain English, the polaris 850 xp code 651 4 means the brain of your power steering system is not getting enough electrical voltage to operate correctly. When the voltage drops too low, the system shuts itself off as a safety precaution, leaving you with heavy, manual steering.
Common Symptoms You’ll Notice
Besides the code on your display, you’ll likely experience one or more of these symptoms:
- Loss of Power Steering: The most obvious sign. The handlebars will become very difficult to turn, especially at low speeds or when stopped.
- Intermittent Power Steering: The steering assist might cut in and out as you ride, which can be unpredictable and dangerous.
- EPS Warning Light: A dedicated warning light for the power steering system will likely illuminate on your dash.
The Usual Suspects: Common Problems with Polaris 850 XP Code 651 4
A low voltage issue sounds complicated, but more often than not, it’s caused by a simple and easy-to-fix problem. Before you start thinking about replacing expensive parts, let’s look at the most common culprits. This polaris 850 xp code 651 4 guide starts with the basics.
The Battery: Your Electrical Heartbeat
This is the number one cause. A weak, old, or failing battery simply can’t supply the steady voltage the EPS system demands. ATVs are notoriously hard on batteries, and even one that can start the engine might not have enough reserve power for the EPS.
Corroded or Loose Connections: The Silent Killers
Electricity needs a clean, tight path to flow. A loose battery terminal, a corroded ground wire, or a shaky connection at the starter solenoid can create resistance, causing a voltage drop that starves the EPS module. This is one of the most common problems we see.
The Charging System: Is Your Stator Pulling Its Weight?
Your Polaris doesn’t just run off the battery; it has a charging system (stator and voltage regulator) that recharges the battery and powers electronics while the engine is running. If this system is failing, it can’t keep up with demand, leading to a low voltage condition.
Damaged Wiring: The Trail’s Hidden Toll
Off-roading is rough. Wires can get rubbed, pinched, or damaged by rocks, branches, or even just vibration over time. A compromised wire in the harness leading to the EPS unit can easily cause this fault code.
Your Toolkit: Gearing Up for the Diagnosis
You don’t need a full professional shop to tackle this job. A few basic hand tools will get you through most of the diagnostic steps. Before you start, gather these essentials:
- Digital Multimeter: This is non-negotiable. You cannot accurately diagnose an electrical problem without one.
- Socket Set and Wrenches: You’ll need these to check and tighten connections, especially on the battery.
- Wire Brush & Terminal Cleaner: For scrubbing away corrosion from battery posts and cable ends.
- Dielectric Grease: To protect your clean connections from future corrosion.
- Safety Gear: Always wear safety glasses and gloves when working with batteries and electrical systems.
How to Polaris 850 XP Code 651 4: A Step-by-Step Fix
Alright, let’s get our hands dirty. Follow this process in order. Don’t skip steps, as the goal is to rule out the simple stuff first before assuming the worst. Here are some actionable polaris 850 xp code 651 4 tips.
Step 1: Safety First & Visual Inspection
Turn the key off and remove it. Before disconnecting anything, do a quick visual check around the battery and engine bay. Look for anything obviously out of place—a disconnected wire, heavy corrosion, or damage.
Step 2: The Battery Health Check
Set your multimeter to DC Volts. Touch the red probe to the positive (+) battery terminal and the black probe to the negative (-) terminal. A fully charged, healthy battery should read at least 12.6 volts with the machine off. If you see a reading of 12.2V or lower, your battery is discharged and is likely the source of your problem. Charge it fully and have it load tested at an auto parts store to confirm its health.
Step 3: Inspect and Clean All Key Connections
Disconnect the negative battery cable first, then the positive. Use a wire brush to scrub the battery posts and the inside of the cable terminals until they are shiny. Follow the thick black negative cable from the battery to where it bolts to the machine’s frame. Remove that bolt, and clean the cable end and the frame contact point to ensure a solid ground connection. Reconnect everything, starting with the positive cable, and make sure it’s all tight.
Step 4: Test the Charging System
With the battery reconnected, start the engine. Let it idle. Now, carefully re-test the voltage at the battery terminals with your multimeter. With the engine running, you should see a voltage between 13.8 and 14.4 volts. If the voltage is below 13V or doesn’t increase when you rev the engine, your charging system (stator or voltage regulator) is likely faulty. This is a more complex repair and a good point to consider professional help.
Step 5: Trace the EPS Wiring Harness
If the battery and charging system check out, it’s time to inspect the wiring. Locate the EPS unit (it’s often under the front plastics near the steering column). Carefully trace the wires leading to and from it. Look for any areas where the harness is rubbing against the frame, is pinched, or has melted from engine heat. Pay close attention to the main connector at the EPS unit itself. Unplug it and check for any green corrosion or bent pins inside.
Step 6: Clear the Code and Test Ride
After performing these checks and corrections, the code will often clear itself. If not, disconnecting the battery for 10-15 minutes will usually reset the system. Take your machine for a slow, safe test ride to see if the power steering is back and the code stays away.
Best Practices to Prevent Code 651 4 from Returning
An ounce of prevention is worth a pound of cure. Following a good polaris 850 xp code 651 4 care guide means you won’t have to deal with this again.
One of the best things you can do is adopt a sustainable polaris 850 xp code 651 4 prevention strategy. This means using high-quality parts and performing regular maintenance to avoid repeat failures and unnecessary waste. A reliable ride is an eco-friendly polaris 850 xp code 651 4 solution because it keeps you on the trail and out of the repair shop.
- Use a Battery Tender: If your ATV sits for more than a week at a time, keep it on an automatic battery tender. This will dramatically extend your battery’s life.
- Apply Dielectric Grease: After cleaning your battery terminals and main ground, apply a thin layer of dielectric grease before reconnecting. This seals out moisture and prevents corrosion.
- Secure Your Wiring: Any time you add accessories or work on your machine, use zip ties to ensure wiring is secure and not rubbing against any sharp or hot components.
When to Put Down the Wrenches and Call a Pro
There’s no shame in knowing your limits. While the majority of 651 4 codes are caused by simple issues, there are times when a professional mechanic is your best bet.
Call for help if:
- Your charging system test fails (testing a stator and regulator requires more advanced knowledge).
- You’ve confirmed the battery, connections, and wiring are all perfect, which strongly points to a failed EPS unit.
- You find significant damage to the main wiring harness that requires splicing or replacement.
Replacing the EPS unit itself is an expensive job, and on many models, the new module needs to be programmed by a Polaris dealer to work with your specific machine.
Frequently Asked Questions About Polaris 850 XP Code 651 4
Can I still ride my Polaris with code 651 4?
Technically, yes, the engine will run. However, you will have no power steering. The steering will be extremely heavy and difficult to control, especially in tight turns or rocky terrain. We strongly advise against riding it, as it can be a significant safety hazard.
Will a new battery always fix code 651 4?
Not always. While a bad battery is the most common cause, a new battery will only be a temporary fix if the real problem is a faulty charging system or a bad connection. A bad voltage regulator will quickly drain and ruin a brand-new battery.
How much does it cost to fix code 651 4?
The cost varies dramatically. A DIY fix could be free if it’s just a loose connection you need to tighten. If you need a new battery, you might spend $80-$150. However, if the diagnosis leads to a failed EPS unit, a professional repair could exceed $1,000 when parts and labor are included.
Is this code related to my winch or other accessories?
It absolutely can be. High-draw accessories like a big winch, light bars, or a stereo system can put a huge strain on your battery and charging system. If the system is already weak, using an accessory can cause the voltage to drop low enough to trigger the EPS code.
Final Thoughts: You’ve Got This
Tackling a diagnostic code like polaris 850 xp code 651 4 can feel daunting, but as you’ve seen, the root cause is often simple. It’s almost always an issue of getting clean, steady power from Point A to Point B.
By working methodically through the battery, connections, and charging system, you can solve this problem yourself 9 times out of 10. You’ll save money, learn more about your machine, and gain the confidence to handle future issues.
Follow these steps, work safely, and you’ll be back to conquering the trails in no time. Ride hard, ride smart, and stay safe out there!
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