0842 Polaris Code - Your Complete Guide To Diagnosing And Fixing It

There’s nothing that kills the thrill of a ride faster than a warning light flashing on your dash. You pull over, run the diagnostic, and see it: the dreaded 0842 polaris code. Your mind starts racing—is this serious? Is my weekend ruined? Is this going to cost a fortune?

Take a deep breath. While any error code is frustrating, this is one you can absolutely tackle yourself with the right guidance. We promise to walk you through exactly what this code means, why it’s happening, and how to fix it without just throwing expensive parts at the problem.

In this complete 0842 polaris code guide, we’ll break down the symptoms, the tools you’ll need, and a step-by-step diagnostic process that will get you from the garage back to the trail in no time.

What Exactly is the 0842 Polaris Code? (And Why You Shouldn’t Ignore It)

At its core, Polaris Fault Code 0842 translates to “Brake Pressure Sensor / Switch Circuit High.”

Let’s put that in plain English. Your Polaris has a small sensor, usually screwed into the brake master cylinder, that tells the machine’s brain (the ECU or ECM) when you’re pressing the brake pedal. The “Circuit High” part means the ECU is seeing a voltage signal from that sensor that is higher than it should be—essentially, it thinks you have the brakes slammed on, even when you don’t.

This isn’t just an annoyance; it’s a critical safety and operational signal. This sensor is responsible for:

Activating Your Brake Lights: The most obvious job. If the sensor is faulty, your brake lights might be stuck on, confusing riders behind you.
Safety Interlocks: On many models, you must press the brake to start the engine or shift out of Park. A bad signal can prevent you from even starting your machine.
Drivetrain Performance: Some AWD systems use the brake signal as an input. A faulty signal can lead to weird 4×4 engagement or performance issues.

Ignoring this code can leave you stranded or create a serious safety hazard on the trail. Tackling it is one of the most important 0842 polaris code best practices you can follow.

Telltale Symptoms: How Your Machine Screams “Code 0842”

Besides the code itself flashing on your display, your machine will give you a few other clues that the brake pressure sensor circuit is acting up. Keep an eye out for these common problems with 0842 polaris code.

Check Engine Light (CEL): This is the most common indicator. The moment the ECU detects the abnormal voltage, it will trigger the warning light.
Limp Mode: To protect itself, your Polaris might enter a reduced power “limp mode,” limiting your RPMs and speed. It’s the machine’s way of telling you to get it checked out ASAP.
Brake Lights Stuck On: Since the ECU thinks the brakes are constantly applied, it will keep the brake lights illuminated, even when your foot is off the pedal.
Failure to Start or Shift: If your model has a brake-to-start or brake-to-shift safety feature, a faulty signal will prevent the system from recognizing you’re holding the brake, leaving you stuck.

Gearing Up: Tools and Parts You’ll Need for the Job

Before you dive in, let’s get your workstation prepped. The good news is you don’t need a full professional shop for this job. Having the right tools makes all the difference.

Must-Have Tools

Digital Multimeter: This is non-negotiable. A simple multimeter is your best friend for testing wires and sensors accurately. It’s the key to diagnosing, not just guessing.
Basic Socket and Wrench Set: You’ll need the right size wrench (often a 19mm or similar) to remove the old sensor.
Flashlight or Headlamp: The brake pressure sensor is often tucked away in a poorly lit spot. Good light is essential for inspecting wires.
Shop Rags: You will likely spill a small amount of brake fluid. Be prepared to clean it up immediately as it can damage plastics and paint.

Essential Parts & Supplies

New Brake Pressure Sensor: Crucially, always verify the correct part number for your machine’s exact year, make, and model. They are not all the same.
DOT 4 Brake Fluid: You’ll need to top off the master cylinder after the swap and potentially bleed the brakes. Check your owner’s manual to confirm the correct fluid type.
Dielectric Grease: A small dab in the new sensor’s electrical connector helps prevent corrosion and ensures a solid connection.

Your Step-by-Step 0842 Polaris Code Guide to Diagnosis and Repair

Alright, let’s get our hands dirty. Follow these steps in order. The goal here is to find the problem without wasting money. This is how to 0842 polaris code diagnostics are done right.

Step 1: The Visual Inspection (The 5-Minute Potential Fix)

Before you test anything, use your eyes. More often than you’d think, the problem is something simple and obvious.

Locate the brake pressure sensor on your master cylinder. Follow the wire harness coming off it as far as you can. Look for:

Chafed Wires: Has the harness been rubbing against the frame, a sharp edge, or another component?
Melted Wires: Is the harness too close to the exhaust pipe?
Corrosion: Pull the connector apart. Are the pins inside green and fuzzy? Is it full of mud or water?
Damage: Did a rock or branch get kicked up and smash the sensor or connector?

If you find a damaged wire or a dirty connector, you may have found your culprit. Clean the connector with electrical contact cleaner and apply dielectric grease. Repair any damaged wires with a proper splice and heat shrink.

Step 2: Testing the Connector and Wiring

If the visual inspection looks good, it’s time to grab your multimeter. This step tells you if the sensor is getting the power it needs to operate.

Turn the key to the “ON” position (engine off).
Carefully unplug the electrical connector from the brake pressure sensor.
Set your multimeter to DC Volts.
The connector will have two or three pins. You need to identify the power, ground, and signal wires (a service manual is great for this, but you can often test to find them).
Place the black probe of your multimeter on a known good ground (a bare spot on the frame or the negative battery terminal).
With the red probe, carefully touch each pin in the connector. You should find one that reads 5 volts (this is the reference voltage from the ECU) and one that reads 0 volts (this is the ground).

If you don’t get a 5-volt reading, the problem is in your wiring harness or, in rare cases, the ECU. If you do get 5 volts and a good ground, your wiring is likely okay, and the suspicion falls on the sensor itself.

Step 3: Replacing the Brake Pressure Sensor

If the wiring checks out, the brake pressure sensor has likely failed internally, causing it to send that constant “high” voltage signal. It’s time to replace it.

Clean the area around the sensor thoroughly. You don’t want any dirt falling into your master cylinder.
Place a few shop rags under the master cylinder to catch any spilled brake fluid.
Have the new sensor unboxed and ready to go, with its new sealing washer in place.
Using the correct size wrench, quickly unscrew the old sensor. Be ready for a small dribble of brake fluid.
Immediately screw the new sensor in by hand to stop the fluid loss.
Tighten the new sensor until it’s snug. Do not over-tighten it! You can damage the threads or the sensor. A gentle, firm tightening is all that’s needed.
Apply a small amount of dielectric grease to the connector pins and plug it in securely.

Step 4: Top Off Fluid, Bleed Brakes, and Clear the Code

You’re almost there! Don’t skip these final, critical steps.

First, open the master cylinder reservoir and top it off with fresh DOT 4 brake fluid. Because you may have introduced a tiny bit of air into the system, it’s a good practice to bleed the brakes. Start with the caliper furthest from the master cylinder and work your way closer.

Once the brakes feel firm, you can clear the code. On many Polaris models, simply starting the machine, letting it run, and turning it off a few times will clear the code if the fault is gone. You can also disconnect the negative battery terminal for about 10 minutes to reset the ECU.

Take it for a short, slow test ride to ensure everything feels right and the check engine light stays off.

Common Problems and Best Practices for the 0842 Polaris Code

Learning from experience is key. Here are some pro 0842 polaris code tips to keep in mind.

The biggest mistake DIYers make is skipping the diagnostic steps and immediately buying a new sensor. While the sensor is a common failure point, you could waste time and money if the real problem is a simple broken wire. Always test before you replace.

This is also a great time to think about your machine’s long-term health. A proper repair is a form of sustainable 0842 polaris code care. When you replace the sensor, properly clean up any spilled brake fluid. This is an easy, eco-friendly 0842 polaris code practice that protects the environment and your machine’s components. Following a good 0842 polaris code care guide like this one ensures you do the job right the first time.

Frequently Asked Questions About the 0842 Polaris Code

Can I still ride my Polaris with code 0842?

It is strongly not recommended. You could be dealing with faulty brake lights, which is a major safety risk. Furthermore, if your machine is in limp mode, you risk getting stranded far from help. It’s best to park it until you can perform the repair.

How much does it cost to fix the 0842 code?

The cost varies. If you do it yourself, you’re only looking at the price of a new sensor (typically $40-$90) and a bottle of brake fluid. If you take it to a dealer or shop, you can expect to pay for the part plus 1-2 hours of labor, likely putting the total cost in the $200-$400 range.

Is the brake pressure sensor the same on all Polaris models?

Absolutely not. They may look similar, but different models use sensors with different thread pitches, connector types, and pressure ratings. Always use your machine’s VIN or specific model information to order the correct part.

My brake lights are stuck on. Is that definitely code 0842?

It is the most likely cause on a modern machine, but not a 100% guarantee. It could also be a short-to-power in the taillight wiring harness itself. Reading the code from the dash display is what confirms the ECU is seeing the fault from the sensor circuit specifically.

Tackling a diagnostic code like 0842 can feel intimidating, but it’s entirely within the reach of a determined DIYer. By following a logical process—inspect, test, and then replace—you can solve the problem efficiently and save a bundle of cash. You’ve got the knowledge and the plan.

Now get out there, get it fixed, and get back to kicking up some dirt. Stay safe and happy riding!

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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.