2018 Ford C-Max Tire Pressure Warning Light Stays On

Common Causes for the Tire Pressure Warning Light in Your 2018 Ford C-Max and How to Resolve Them

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Tire Leaking Air
0%
30% chance it's the
Wheel Leaking Air
0%
15% chance it's the
Tire Pressure Monitoring System
0%
15% chance it's
Something else
The most common reasons a 2018 Ford C-Max tire pressure warning light stays on are a leaking tire, a wheel that no longer holds air, or a faulty tire pressure monitoring system.
  • Tire Leaking Air: A puncture, valve stem issue, or rim damage can cause a tire to leak air, leading to loss of pressure.
  • Wheel Leaking Air: A puncture or damage to the tire or rim can cause air to leak, resulting in a loss of tire pressure.
  • Tire Pressure Monitoring System: A malfunctioning tire pressure monitoring system can be caused by faulty sensors or a dead battery in the sensor units.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2018 Ford C-Max tire pressure warning light stays on?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

When a tire pressure monitoring sensor fails, the tire pressure monitoring system control module will recognize a loss in communication and turn on the warning lamp which indicates the failure. This is most often the case. However, the tire pressure monitoring sensor may also fail by reporting incorrect tire pressures. This could cause a flat tire to go unrecognized, or a properly inflated tire to signal a low or high tire pressure warning.

When a relearn is needed, for any reason, the TPMS warning light will illuminate, and many vehicles will display a message relating to the TPMS system being inoperative or loosing communication. It is important to keep a watchful eye on tire pressures when this system is having issues because there is no warning available for underinflation or overinflation of the tires.

Wheels offer very few symptoms, but these symptoms should never be ignored. Visible cracks on the wheels may appear, especially after hitting a large bump, Most often, this will also be accompanied by loss of air from the tire on that wheel. Also, vibration in the steering wheel is very common when the tire is out of balance, and improper wheel nuts or bolts can cause creaking and popping noises to develop. Again, there are very few symptoms, but they should not be ignored.

The only symptoms requiring diagnosis for the tire pressure monitoring system warning lamp is if the warning lamp has illuminated while the tires have correct air pressure, or if the air pressure for the tires is out of specification and the warning lamp is off. This is because the overwhelming majority of cases where the TPMS lamp illuminates is due to the change in ambient temperature.

What steps should I take to diagnose the tire pressure warning light issue on my 2018 Ford C-Max?

To effectively diagnose the tire pressure warning light issue on your 2018 Ford C-Max, begin with a thorough check of the tire pressure in all four tires using a reliable tire pressure gauge. Ensure that each tire is inflated to the recommended levels specified in your vehicle's manual, as improper inflation is a common cause of warning lights. Next, conduct a visual inspection of the tires for any signs of damage, such as punctures, cuts, or bulges, and look for foreign objects that may be lodged in the tread. If the tire pressure is correct and the tires appear undamaged, proceed to reset the tire pressure monitoring system following the instructions in your owner's manual, as this can sometimes resolve temporary issues. However, if the warning light remains illuminated after these steps, it may indicate a more complex problem, such as a faulty sensor. In such cases, seeking assistance from a qualified mechanic or dealership is advisable for a comprehensive diagnosis and repair. By following this diagnostic approach, you can systematically address the tire pressure warning light issue and ensure your vehicle's safety and performance.

What could be causing the tire pressure warning light to stay on in a 2018 Ford C-Max?

When the tire pressure warning light stays on in a 2018 Ford C-Max, it can indicate several underlying issues that need attention. The most common reason is low tire pressure, which can be easily checked and adjusted to the recommended levels. If the tire pressure is sufficient, the problem might stem from a faulty tire pressure sensor that may need replacement. Additionally, sensor calibration issues can lead to incorrect readings, and recalibrating the sensors according to the vehicle's manual can often resolve this. Electrical problems, such as wiring faults or blown fuses related to the tire pressure monitoring system, can also cause the warning light to remain illuminated. Lastly, a malfunction within the tire pressure monitoring system itself may require diagnostic testing to identify and fix the issue. Addressing these potential problems is vital for ensuring the safety and proper functioning of your vehicle.

What should I do if the tire pressure warning light on my 2018 Ford C-Max stays on?

When the tire pressure warning light on your 2018 Ford C-Max remains illuminated, it is crucial to take immediate action to avoid serious safety risks and potential damage to your vehicle. Ignoring this warning can lead to decreased traction, increased tire wear, and even tire blowouts, which can compromise your safety on the road. Start by checking the tire pressure in all tires, including the spare, using a reliable gauge to ensure they are inflated to the recommended levels. If you find any tires underinflated, inflate them accordingly, as proper tire pressure is essential for optimal vehicle performance and safety. Additionally, inspect your tires for any visible damage, such as punctures or bulges, which could indicate a need for repair or replacement. Once you have addressed any pressure issues and confirmed the integrity of your tires, resetting the tire pressure monitoring system is often necessary to clear the warning light. If the light persists despite these efforts, it is imperative to consult a qualified mechanic, as there may be a deeper issue with the monitoring system that requires professional attention. Taking these steps not only ensures your safety but also helps maintain the longevity and efficiency of your vehicle.

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