If your dashboard suddenly lights up like a Christmas tree and your Drive gear indicator starts flashing, you are likely dealing with a frustrating honda crv check engine codes issue, specifically the dreaded honda crv code p0845 p0847. At Vroomdan, we know how stressful it is when your family SUV begins shifting harshly or slipping between gears. Fortunately, this common issue is highly manageable, and diagnosing it can save you from a massive dealership bill while clearing the path to enjoy the hidden features of your reliable daily commuter.
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In This Guide
- Diagnostic Codes Decoded: Understand why the P0845 and P0847 diagnostic trouble codes trigger a flashing dashboard light.
- Step-by-Step Replacement: A complete, beginner-friendly DIY guide to safely replacing transmission fluid pressure switch B.
- OEM Parts & Diagnostics: Learn how to source the correct factory components and avoid cheap, unreliable aftermarket sensors.
- Preventative Maintenance: Discover simple fluid maintenance routines designed to protect your SUV’s clutch packs.
Troubleshooting the Honda CRV Code P0845 P0847 and Replacing Switch B
A faulty 3rd clutch transmission fluid pressure switch is the primary culprit behind these specific error codes.
When this switch fails, the Powertrain Control Module, or PCM, cannot accurately monitor the hydraulic pressure in the third clutch circuit.
This failure triggers a safety fallback mode, causing the drive indicator to blink on your dashboard.
Before you panic about needing an entirely new transmission, you can execute a straightforward honda crv p0845 p0847 fix right in your own garage.
Completing this repair will quickly restore your SUV’s smooth shifting performance.
Prerequisites and Tools Needed
Replacing the pressure sensor is a beginner-to-intermediate DIY task that takes about 45 to 60 minutes.
You will need a few basic tools to complete the job safely and effectively.
Prepare a 10mm socket wrench to remove the plastic splash shield underneath the engine bay.
You will also need a 22mm deep socket or a specialized open-ended wrench to unscrew the pressure switch itself.
Keep a new Original Equipment Manufacturer, or OEM, replacement switch and a matching aluminum crush washer nearby.
Do not forget to wear protective safety glasses and mechanics gloves to safeguard yourself from hot oil.
Step-by-Step Instructions
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Safely Elevate and Secure Your CR-V
Park your SUV on a flat, level surface and engage the emergency parking brake fully.
Use a heavy-duty hydraulic floor jack to lift the front end of the vehicle.
Always place robust jack stands under the designated frame rails before crawling underneath.
Never rely solely on a hydraulic jack to support the vehicle while you work.
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Remove the Driver-Side Wheel and Splash Shield
Unscrew the lug nuts to remove the front driver-side wheel for easier physical access.
Locate the plastic splash shield inside the wheel well fender line.
Carefully remove the 10mm bolts and plastic push pins securing the inner fender liner.
Peel back the liner gently to avoid snapping the brittle plastic clips.
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Locate and Disconnect Transmission Fluid Pressure Switch B
Look past the frame rail to find the honda crv transmission mounts and the transmission casing.
You will see the honda crv transmission fluid pressure switch b plugged into the side of the case.
Press the locking tab on the electrical connector and pull it straight off the sensor.
Inspect the wire harness connector closely for any signs of corrosion, dirt, or oil intrusion.
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Remove the Faulty Pressure Sensor
Slide your 22mm deep socket over the old switch body carefully.
Turn the socket counterclockwise to break the sensor loose from the transmission casing.
Be prepared for a small amount of honda crv transmission fluid to drip out when the switch is unscrewed.
Keep a clean shop rag directly under the mounting hole to catch any sudden spills.
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Install the New OEM Pressure Switch B
Slide the new aluminum crush washer onto the threads of your new replacement switch.
Thread the new switch into the casing by hand first to prevent cross-threading the soft aluminum casing.
Tighten the switch using your torque wrench to the official Honda specification of 14 lb-ft.
Reconnect the electrical harness connector until you hear a distinct clicking sound.
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Reassemble and Perform a Road Test
Reinstall the plastic splash shield and secure all the plastic push pins.
Mount the front wheel back onto the hub and tighten the lug nuts to 80 lb-ft.
Lower the vehicle safely to the ground and clear any stored engine codes using an OBD-II scanner.
Take your CR-V for a short drive to ensure the shifting is smooth and the warning lights remain off.
Vroomdan Community Support
At Vroomdan, we are dedicated to helping SUV owners avoid overpriced dealer diagnostics through practical DIY instructions.
You can find more helpful maintenance tips on our main site at Vroomdan.
Expert Deep-Dive: Understanding Transmission Codes P0845 and P0847
To understand the root cause of these codes, we must look at how the 5-speed automatic transmission functions.
The PCM relies heavily on oil pressure switches to confirm that specific clutch packs have engaged successfully.
The code P0845 represents a general circuit failure within the transmission fluid pressure sensor B system.
The code P0847 specifically indicates that the voltage reading from this sensor is stuck low.
According to certified ASE mechanics, a p0845 p0847 code honda crv error usually points to an electrical failure inside the sensor rather than mechanical internal damage.
The internal diaphragm of the switch wears out over time due to thousands of pressure cycles.
This wear causes the internal electrical contacts to fail, sending erroneous readings to the PCM.
When the PCM detects an implausible voltage signal, it immediately triggers the defensive fail-safe protocol.
This protocol activates a flashing “D” indicator to warn the driver of the electrical pressure discrepancy.
Deciphering the Blinking D Light and Fluid Quality
The notorious honda crv blinking d light fluid sensor system acts as a check engine light specifically for the transmission.
Ignoring this flashing warning light can eventually lead to harsh shifting and premature clutch wear.
Many owners of a honda crv code p0847 discover that dirty fluid degrades the sensor electrical contacts.
Metallic debris suspended in old fluid can bridge the gap inside the sensor housing, shorting out the circuit.
If you purchase a used honda crv code p0845 p0847 issue might already be present due to neglected fluid service intervals.
Always inspect the physical condition of the fluid before buying a pre-owned SUV.
Practical Application Guide and Transmission Fluid Maintenance
Preventative maintenance is your absolute best defense against costly transmission repairs.
The Honda factory service manual strongly recommends performing a simple fluid drain and fill every 30,000 miles.
You can easily check the level and color of your fluid using the honda crv transmission dipstick located near the battery box.
Healthy fluid should exhibit a bright pinkish-red color and be completely free of burnt odors.
If the fluid appears dark brown or black, you need to perform a series of drains to refresh the system.
Always calculate the overall honda crv transmission fluid change cost before deciding between a DIY job or professional service.
Never perform a high-pressure chemical flush on a high-mileage Honda transmission, as this can dislodge debris and clog internal fluid passages.
Overcoming Common DIY Mistakes During Replacement
One of the most common mistakes DIYers make is buying cheap, unbranded aftermarket pressure switches online.
Aftermarket switches often feature incorrect internal calibration specs, causing the warning light to return within days.
Always invest a few extra dollars to purchase a genuine OEM Honda sensor (Part Number 28600-RCL-004 or 28610-RKE-004 depending on your year).
Another frequent error is overtightening the sensor into the aluminum transmission case.
The threads on the casing are extremely delicate and can strip easily if you do not use a calibrated torque wrench.
Finally, never forget to install the fresh aluminum crush washer to prevent slow, persistent fluid leaks.
Taking your time during this honda crv p0845 p0847 fix guarantees a leak-free repair that lasts for many years to come.
Frequently Asked Questions
You should avoid driving long distances when the Drive light is actively flashing on your dashboard.
The flashing light indicates the transmission has entered a limp-home safety mode to prevent mechanical damage.
While you can safely drive a short distance home or to a nearby repair shop, continued driving can cause harsh gear engagement and accelerate clutch wear.
On most CR-V model years, pressure switch B (also known as the 3rd clutch pressure switch) is located on the front of the transmission casing.
You can access it easiest by removing the front driver-side wheel and peeling back the plastic inner splash shield.
It is positioned close to the starter motor and has a single-wire electrical connector plugged into its head.
Yes, in the vast majority of cases, replacing a faulty pressure switch resolves shifting hesitation and clears the error codes.
However, if the codes return immediately, you may be dealing with damaged wiring, a failing PCM, or severe internal mechanical wear within the clutch packs themselves.
“I’ve driven a CR-V for 4 years and didn’t know this existed.”
— The most common reaction when this article is shared
Did you know your backup camera has a hidden top-down ‘drone view’? Or that your cruise control automatically downshifts on steep mountain hills to save your brakes?
bryansgarage.com · Bryan Mark
Conclusion
Replacing a bad transmission pressure switch is a straightforward project that quickly restores your peace of mind.
Ready to get the most out of your SUV? Check out more guides on Vroomdan or email us at contact@vroomdan.com — our team is here to help you discover more SUV secrets and maintenance guides.
Disclaimer: Always consult your official Honda Owner’s Manual before performing any DIY modifications. Information provided is for educational purposes and depends on specific vehicle model years, trim levels, and individual modifications.