Seeing a flashing check engine light on your dashboard with a honda crv code p0117 p0118 sensor error can trigger instant panic, but Team Vroomdan is here to help you solve this engine coolant temperature sensor malfunction quickly. Before you spend hundreds of dollars on diagnostic fees, let’s explore how to resolve this sensor fault at home and discover some hidden CR-V features that many owners don’t know about.
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bryansgarage.com · Bryan Mark
In This Guide
- Understand the core differences between the low voltage (P0117) and high voltage (P0118) coolant sensor faults.
- Follow a direct, step-by-step tutorial to replace your Engine Coolant Temperature (ECT) sensor at home.
- Learn how to test your sensor using a digital multimeter to confirm a failure before buying parts.
- Discover common replacement mistakes that could cause severe engine overheating issues.
Decoding and Fixing Your Honda CRV Code P0117 P0118 Issues
Dealing with unexpected engine codes can be incredibly frustrating and stressful when you rely on your vehicle for daily family commutes.
The Engine Coolant Temperature (ECT) sensor 1 is a critical thermistor that communicates directly with your Honda’s Engine Control Unit (ECU).
When the ECU receives erratic signals outside of normal operating parameters, it illuminates the check engine light and disables features like remote start.
Luckily, replacing a faulty sensor is a highly manageable task that you can easily execute in your own driveway.
Prerequisites and Tools Needed
- A new OEM or high-quality aftermarket honda crv coolant temperature sensor
- A 19mm deep socket or open-ended wrench
- A 10mm socket and ratchet (for battery terminal and plastic engine covers)
- Genuine Honda Type 2 Blue Coolant
- A clean drain pan and safety glasses
- Shop towels and a small wire brush
- Time required: 45 to 60 minutes
Step-by-Step Replacement Instructions
1. Cool the Engine and Prep the Workspace
Working on a hot cooling system can result in severe, painful skin burns from pressurized boiling liquid.
Park your CR-V on a flat surface and allow the engine to sit idle for at least two hours before starting.
Disconnect the negative battery cable using your 10mm wrench to prevent any electrical shorts during the repair.
Locate the ECT sensor 1, which is typically threaded into the cylinder head cooling passage on the rear of the engine block.
2. Disconnect the Electrical Harness
Gently press the plastic locking tab on the electrical connector and pull it away from the sensor body.
Inspect the internal metal pins of the wire harness for green oxidation or corrosion.
Use a specialized electrical contact cleaner spray if you spot any dirt or residue inside the harness connector.
3. Remove the Failing Sensor
Position your clean drain pan directly underneath the engine area to catch any escaping coolant.
Place your 19mm socket over the old sensor and turn it counterclockwise to loosen it.
Keep your new sensor ready in your hand as you completely unthread the old unit.
Quickly insert the new sensor to block the open port and prevent excessive coolant loss.
4. Thread and Torque the New Sensor
Verify that the new metal crush washer or rubber O-ring is properly positioned on the new sensor body.
Thread the new sensor into the cylinder head by hand clockwise to avoid cross-threading the delicate engine threads.
Tighten the sensor using your wrench until it is snug, aiming for approximately 12 to 15 lb-ft of torque.
Push the electrical harness back onto the sensor until you hear a distinct clicking sound.
5. Bleed the Cooling System and Clear Codes
Refill the radiator or expansion tank with fresh Honda Type 2 Blue Coolant to replace any spilled fluid.
Leave the radiator cap off and start your CR-V to let the cooling system bleed out trapped air bubbles.
Set your interior climate control system to maximum heat with the fan on low to open the heater core valve.
Once bubbles stop appearing in the filler neck, reinstall the radiator cap tightly.
Use an OBD2 scanner tool to clear the saved codes and verify that the dashboard warnings do not return.
At Vroomdan, we are dedicated to helping family SUV owners master their own repairs to build confidence and bypass outrageous dealership costs.
Analyzing the Differences: P0117 vs P0118 on Your Honda CR-V
The overwhelming sense of relief you will feel when you identify the exact diagnostic trouble code makes troubleshooting highly rewarding.
While both codes refer directly to your primary coolant sensor, they signal completely opposite electronic system states.
A triggered p0117 code honda crv indicates that the ECU is receiving an abnormally low voltage input from the temperature circuit.
This typically means the circuit is shorted to ground, or the sensor has failed internally in a closed state.
Conversely, a triggered p0118 code honda crv points to an abnormally high voltage signal being registered by the vehicle’s computer.
This state almost always points to an open circuit, such as a fully severed signal wire or a loose plug connection.
Experienced mechanics from the CR-V Owners Club note that rodent damage to the sensor wires is a common cause for this issue.
Understanding these voltage states helps you quickly rule out deep mechanical damage in favor of simple electrical repairs.
How to Perform a Honda CRV Coolant Sensor Test
Before throwing hard-earned money at a new part, you can run a definitive honda crv coolant sensor test using a digital multimeter.
Set your multimeter tool to the ohms resistance setting to measure the sensor’s response to thermal shifts.
Touch your meter’s probes directly to the two main pins inside the ECT sensor housing.
At a cool room temperature of 68 degrees Fahrenheit, a healthy Honda sensor should register roughly 2,000 to 2,500 ohms of resistance.
As the engine warms up to 176 degrees Fahrenheit, that resistance should naturally drop to approximately 300 ohms.
If your multimeter indicates infinite resistance or an open circuit, you have located a definitive honda crv coolant temperature sensor fault.
Performing this simple bench test prevents you from replacing functional sensors when the real culprit is a broken wiring harness.
The Used Car Warning: Why You See a Used Honda CRV Code P0117 P0118
If you recently purchased a pre-owned vehicle, encountering a used honda crv code p0117 p0118 is a fairly common occurrence.
Previous owners often neglect routine fluid flushes, allowing mineral deposits to coat the sensitive tip of the coolant sensor.
Over time, these heavy deposits insulate the sensor and prevent it from reading correct engine thermal fluctuations.
In other cases, budget-conscious sellers may have used a generic universal sensor that is not fully compatible with Honda’s electrical tolerances.
Replacing the generic unit with an OEM Honda sensor acts as a permanent honda crv ect sensor code fix.
CR-V Cooling System Maintenance and Pricing Overview
Maintaining your cooling system avoids the nightmare of a warped cylinder head or cracked engine block.
Regular preventive maintenance keeps your CR-V running efficiently while keeping more money in your wallet.
| Service Procedure | Estimated DIY Cost | Average Dealership Cost |
|---|---|---|
| ECT Sensor Replacement | $25 – $45 | $180 – $260 |
| honda crv coolant flush | $30 – $50 | $140 – $190 |
| honda crv thermostat replacement | $35 – $60 | $220 – $310 |
| honda crv radiator replacement | $110 – $180 | $450 – $700 |
As illustrated above, mastering these simple diagnostic and repair procedures can save you hundreds of dollars in labor fees.
We recommend performing a full coolant flush every 100,000 miles to keep the internal passages clean and free of scaling.
Critical Mistakes to Avoid During Your ECT Sensor Replacement
Making a careless error during assembly can transform a quick repair into a stressful mechanical emergency.
The most common mistake DIY beginners make is over-tightening the sensor into the aluminum cylinder head.
The threads on the engine block are soft aluminum and will strip easily under excessive mechanical force.
Another frequent issue is ignoring the bleeding process, which traps a large pocket of air inside the engine cylinder head.
This trapped air pocket prevents coolant from circulating and causes rapid hot spots that can ruin your head gasket.
Lastly, never substitute genuine Honda Type 2 coolant with generic green fluids, as they contain silicates that damage Honda water pump seals.
Frequently Asked Questions
Can I drive my Honda CR-V with a P0117 or P0118 code?
You should avoid driving your CR-V with active temperature codes because the ECU cannot monitor engine heat accurately.
Without an accurate reading, your engine can overheat rapidly without warning, leading to catastrophic block failure.
Where is the ECT Sensor 1 located on my CR-V?
On most 2.4L and 1.5L Turbo engines, ECT Sensor 1 is located on the rear or side of the cylinder head near the thermostat outlet.
Do not confuse this with ECT Sensor 2, which is located at the bottom of the radiator to control the cooling fans.
Why did my check engine light stay on after replacing the sensor?
Your vehicle’s ECU often requires several driving cycles to verify the repair before resetting dashboard warnings on its own.
You can instantly clear honda crv check engine codes by using an OBD2 scanner or disconnecting the battery for ten minutes.
“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 your coolant sensor is a simple, highly rewarding DIY fix that keeps your engine safe.
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.