Road Departure Mitigation System Problem After Flat Tire in My Honda

Are you stuck with a Road Departure Mitigation System alert after replacing a flat tire? A lot of Honda owners have been reporting this issue after changing their flat tires with spare ones.

Road departure mitigation system problem message highlights

• Common reasons:ACC problems, flat tire, other problems
• How to fix:check the radar sensor, check the camera, confirm the tires are good, read the codes
• Possible consequences:ACC, emergency brakes won't work
• Priority level:Low
• Can you drive?Yes
• DIY repair:Possible
• Repair price range:$0-$250

What Do you need to Know About the Road Departure Mitigation System in Honda Cars?

The Road Departure Mitigation System is a vehicle safety system designed to detect if drivers are drifting off from the lane. It uses a camera mounted on its windshield to detect lane and road marks.

Once it detects the vehicle leaving the lane, your dashboard will start showing the Road Departure alert, and your steering wheel will start vibrating. Additionally, the system will prevent it from drifting. And as soon as the system concludes your vehicle is going off the lane, the system will automatically apply the brakes. By doing this, the system helps the driver steer back to the lane and reduce the risk of accidents, especially when turning on curves and during challenging weather.

To make this possible, RDMS work with other technologies in Honda Vehicles.

Technologies and Safety Mechanisms that work with Honda RDMS

The RDMS does not work alone. It works with other technologies to stabilize your vehicle and prevent it from going off its lane by using sensors that communicate with the vehicle's computer. These sensors are scattered throughout the vehicle and send the reading to the main computer. With all the components working together, the computer can control the traction, speed, steering, brakes, and wheels.

• Tire Pressure Monitoring System (TPMS)
• The Vehicle Stability Assist (VSA)
• Collision Mitigation Braking System (CMBS)
• Lane Keeping Assist System (LKAS)
• Blind Spot Information System (BSIS)

What do we love about the Honda RDMS?

RDMS and other innovations applied to your Honda vehicle have undergone years of research and development. While some drivers deem this technology annoying or unnecessary as the vehicle takes charge of control, it offers many benefits.

• It helps reduce the risk of accidents.
• It encourages safe driving.
• Driving becomes more efficient.
• The system provides better control.
• It encourages responsible driving.
• RDMS increases awareness of surroundings.

Why RDMS Shows Up After Fixing Flat Tire- What's the Problem?

As a safety mechanism, getting the Road Departure Message after replacing a flat tire seems odd. Imagine fixing a flat tire problem only to result in another problem.

As a driver of a vehicle with VSA, the first thing you may think of when replacing your tire is- should you replace only one tire, two rears, two fronts, or all of them?

Honestly, replacing your tire comes with many consequences, not only because of tire mismatch.

1) Tire Size Mismatch

After replacing your tire, the old and new tire sizes will have imbalanced treads. Mismatched tires can result in your vehicle drifting out of its lane. When the RDMS camera detects your vehicle is moving out of the lane, your panel will show the Road Departure Mitigation alert.

To fix this issue, ensure your vehicle tires have the same size and type. Next, check all their tire pressures. It should be by the tire pressure set by Honda. After the tire pressure, reset the Road Departure Mitigations System. Do this by pressing the reset button or turning it off and then on again.

Finally, check if the system detects the road lanes correctly. Doing this will help you ensure the system is working well.

2) Damaged Sensors

The RDMS relies on different sensors to determine if the vehicle is going off the lane. Sensors such as the ones found in cameras, radars, and lidars ensure the system works efficiently. Other essential sensors that work with RDMS are wheel speed sensors, steering angle sensors, and lateral acceleration sensors. These sensors can send wrong signals to the vehicle's computer and trigger a Road Departure Mitigation notice when damaged.

Perform a visual inspection of your sensors if you know where to find them. Look for dirt, damage, or corrosion on the sensors. Additionally, your best way to find which sensors are faulty is to scan them with OBD II or bring your vehicle to your trusted technician for this scanning. 

3) Incorrect Tire Pressure

After replacing your flat tire, the wheels may have imbalanced tire pressure. Having mismatched tire pressure can trigger the RDMS alert. When one tire has lower or higher pressure, the other one may shift more or closer to the ground than the other tire. A slight difference can easily trigger the RMDS alert. To address this issue, you can set the tire pressure to Honda's recommended tire pressure setting.

4) Wheel Misalignment

Sometimes tires are set off from alignment after changing tires. With misaligned tires, the RDMS may show the differences between the speed of unreplaced and replaced tires. When it does, the system will tag these findings as a threat or potential hazard. But in most cases, you will not know that this is a case of misaligned wheels.

Many methods can help you diagnose wheel alignment after replacing a tire. For accuracy, we would advise bringing your Honda vehicle to your trusted service shop to ensure your wheels point in one direction.

You can start a visual inspection to check if you have set the wheels correctly. Next, check your tire pressure.  Take note of abnormal patterns that you can notice when steering. See if it goes on a straight line or to the side on its own.

The best way to fix this issue is to bring it to your technician for scanning to have an accurate diagnosis.

5) Incorrect Tire Tread Depth

Having incorrect tread depth between wheels after changing one of them during a flat tire can trigger the RDMS alert. Tread depth is the tire's vertical measurement from the surface of the tread rubber to the bottom of its deepest grooves.

Of course, the used tires may have been in use for longer, and their tread must have decreased. Comparing it with the newly-installed tire may create a difference that the RDMS camera may notice. If so, the system will tag it as a threat that can cause the vehicle to go out of the lane.

To avoid this, install a tire with the same tread depth as the other tires.

6) Incorrect Suspension Component Adjustments

When changing flat tires, you need to adjust the suspension components, such as springs and shock settings, to compensate for the newly installed tires. You have to do this since the new tire may be larger than the others. This event could alter the ride height and trigger the RDMS alert.

To avoid this, ensure that the adjustments are by Honda's recommendation. Set the ride height to the correct adjustment, including the camber and toe angles. You must ensure the suspension has proper alignment and equal tire size.

7) Incorrect Tire Pressure Monitor Reset

When replacing any tire in your Honda vehicle, you need to reset your Tire Pressure Monitor System (TPMS) to ensure it works in coordination with the RDMS. Skipping this step can lead to false alarms and signals. One of these false alarms can trigger RDMS and tell that your tire pressure is not within the required range. This alert will not disappear until you fix it.

To fix this issue, measure all your tire's pressure using a tire gauge and take note of them. After setting them to accurate PSI, reset your TPMS setting.

Look for the TPMS reset button, which can either be in the center console, glove compartment, or trunk.

Press this button until it turns off. Wait for a few minutes before turning it on again. Test drive your vehicle to let it recalibrate.

8) Vehicle Software Not Updated

The RDMS, with its sensors and cameras, relies on software updates to adapt to newer technologies once updated. But when the system uses an outdated version, it may be unable to detect the vehicle when it is veering off its lanes or may be unable to pick up correct readings. It may provide wrong information and false alerts to the driver unnecessarily.

The best thing you can do is to bring your vehicle to your service technician to keep your software updated. 

Final Thoughts

Road Departure Mitigation System is a helpful technology to keep your vehicle in lane, especially if you are riding on a challenging whether or turning on sharp curves. However, changing your flat tire could disrupt its functionality, especially when the replaced tire mismatches the old tire.

You can check everything to ensure that you have balanced wheels: the size, tread, tire pressure, and alignment. Also, check the sensors to see if they are in good shape. Finally, reset your RDMS system before using them again. And if you are not comfortable with all the diagnosing methods, you can always seek professional help from your technician.