In today’s setting, tire pressure monitoring systems are part of the structure of most vehicles’ fuel-efficiency systems. And whether you like it or not, they are here to stay.
It is just the same as any other electrical component around that when it fails at some point in your car’s life; you will need to spend bucks for it to get fixed.
But if you want to be proactive and safe at all times, you can do so by investigating the problem for yourself and locating the faulty part.
By doing so, you will save time and money instead of going to the repair shop and waiting for it to be fixed.
With that in mind, what are you supposed to do when one of your sensors indicates a problem and specifically that you are facing a tire pressure sensor fault situation?
What is a tire pressure sensor?
A tire pressure sensor is a small electronic device installed inside your car’s tires. It is used to wirelessly monitor the air pressure in real-time while you are driving.
Tire pressure sensors have been integrated into a Tire Pressure Monitoring System (TPMS) of automobiles and vehicles for where they are made mandatory in the US.
These tire pressure sensors are often attached to each of the valve-stem assemblies of your tries and are given life by using a battery.
What are the types of tire pressure sensors?
Two common types of tire pressures sensors are used in the car industry.
The first one is the valve type on which the valve stem and the sensor are in the same unit, while the band sensor is mounted with a metal band in the insides of the rim.
What is the use of a tire pressure sensor?
Having your tires inflated to the wrong pressure can significantly reduce your vehicle’s fuel efficiency.
Over and under-inflated tires can also increase the braking distance required to bring your car to a stop. This leads to uneven tire wear and unnecessary early tire replacement costs.
A tire pressure sensor helps to warn you when you are driving with low-pressure tires. These tire pressure sensors were created to prevent that from happening.
Where can I find the tire pressure sensor?
Generally, tire pressure sensors are integrated inside your car tires. Once you have onto your tire air valve, you can see it instantly.
It can often be seen as a nut placed around the valve. But the best to find the tire pressure sensor is to remove each tire from the rim or read your car’s manual or go to a repair shop to ask for guidance.
How does a tire pressure sensor work?
The tire pressure sensor sends the data via low-frequency radio to the vehicle’s internal computer or dashboard.
It displays a pressure sensor fault message in the unit of pounds per square inch (psi), and it flashes a yellow warning light indicator in your dashboard as soon as the air pressure in tires reaches a certain threshold.
And that is usually 2 to 5 psi under the recommended pressure of every TPMS system.
Depending on the car manufacturer, the icon could be anything from a tire icon to the TPMS (tire pressure monitoring system).
How Does a Tire Pressure Sensor Fault Message Appear?
When a tire pressure sensor detects a low tire pressure, it sends a signal to the car’s computer, illuminating a dashboard light. This blinking yellow warning light indicates a tire pressure sensor fault message.
This tire pressure light is usually bright yellow and fashioned like an exclamation point (!) within a “U” sign. This is the driver’s warning to check their tires since one may be flat or just underinflated.
When things go wrong, what to do when you see a tire pressure sensor fault message?
It will be challenging to identify the incorrect or faulty tire pressure sensor due to various factors. Most vehicles have four similar tpms sensors, and you won’t tell which one is defective.
Here are some things that you need to do once you see a tire pressure sensor fault message:
The Standard Protocol: Check the tire pressure
Whenever you see an indicator in your TPMS system that there is a tire pressure sensor fault message, the first thing to do is to pull over and confirm if one of your tires looks like it’s under-inflated.
Check every tire with a tire pressure gauge and see the tire pressure label to get the correct pressure level.
If you observe that one of your tires is flat, then all you need is to install a spare tire from your trunk and get the repair kit to fix it yourself or get your car to an auto repair shop to get it fixed.
If you can see that there is still some air inside, you may have a slow leak. If you have brought yourself a portable inflator with you, that should do the trick by simply putting more air in the problematic tire.
With that, you can still drive for a short distance as long as the tire is not squeezed between the edge of the rim and the pavement. Then get yourself to find the nearest auto-shop as soon as possible for it to be checked thoroughly.
As much as possible, don’t ever try to drive with a flat tire because it can damage your rim. You will lose control of your vehicle, and it can lead to accidents.
When in doubt, always install your spare tire before going any further.
However, if all of your tires look fine, you could have a tire pressure sensor problem. This indicates that one of the tire pressure sensors is broken that could send a false low-pressure signal.
Causes of Tire Pressure Sensor Problem
- No communication between the sensor and the TPMS module
- Internal circuit problems
- Broken sensor because of an improper tire mounting technique
Resetting with Tire Pressure Button or with a Scanner
Once everything is fixed, and you see that your tires are good to go, you need to reset the TPMS system via the reset button manually.
Other cars can do this by driving for 15 minutes to let the lights go out. Often so, you will need a diagnostic tool to make it away.
Look out for the blinking light
A flashing TPMS light usually means that the TPMS system is not receiving data from one or all sensors.
To identify the cause of this problem, you’ll have to get your hands on a professional OBD2 or a TPMS scan tool with programming capabilities.
Scanning for DTCs
In most cases, when the TPMS light is blinking, it will record a DTC (Diagnostic Trouble Code) in your car’s ECM.
You will need a diagnostic scanner for this to get the Diagnostic Trouble Code on your car. These TPMS system error codes can be found on your vehicle’s TPMS control module.
Scanning for DTCs could speed up the process, and this will give you a good indication of what the problem is, where it’s located, and what you should check up on first.
Sample DTC Codes
C0750 Code
This code will indicate that the Tire Pressure Monitor (TPM) system sensor is not transmitting or one of your sensors is not sending anything to the module.
Your next move should be to inspect and test the sensors.
U0127 code
This code will indicate that there is a lost communication with the tire pressure monitor module, and it could leave a problem between the TPMS module and the ECM.
In such a situation, you should look for an open circuit between the module and the ECM before suspecting a sensor problem.
Reprogramming the sensors
After getting the DTC error because of a faulty sensor, the most feasible way is to reprogram every one of your sensors one by one and see if it is working again.
Wireless devices tend to log out and break the link with the other devices they are paired with for no apparent reason. Think about your wireless speakers, PC printers, and other Bluetooth-enabled devices, and you’ll understand what I mean.
So try pairing everything together again first before you bring out the big guns to troubleshoot a potentially complicated problem for nothing.
To do that, you’ll either need a professional TPMS reset tool or a cheap one with instructions. You will also need the correct procedure to enter your car’s TPMS teaching mode. (“Teaching” here means “programming” the sensors.)
It could also be called “learning mode” or something similar, depending on the car manufacturer.
Be aware of what functions are included for what car brand when you buy a TPMS reset tool. They don’t all have the same features for all car models, and some don’t allow the teaching of new sensors.
Every car is different, and they all have their procedure to enter teaching mode.
For example, for older GM vehicles, you need to press the LOCK and UNLOCK button on the key for 5 seconds or until the horn sounds twice. And Ford F-series requires you to press the brake pedal once, push the START button five times, press the brake pedal again, and push the START button again six times.
Professional TPMS scan tools, on the other hand, can easily record and teach sensors using only the OBD port or a Bluetooth connection.
So, you don’t need to put your car in teaching mode before doing anything. Record the sensor signals one by one, then plug in the TPMS tool in the OBD port and wait for the teaching confirmation.
Identifying a faulty sensor
If, even after reprogramming everything, you still have an error message in the information center or a blinking TPMS light, one of your sensors is probably faulty. It probably stopped sending any signal back to the unit.
To find which sensor needs to be replaced, take out your OBD2 scan tool and go to the “live data” section, find the TPMS sensor data and look out for any irregularities.
Before doing this, make sure all your tires are correctly inflated first, using a hand-held tire gauge. And once you are sure that all your tires are at the correct psi, any incorrect pressure reading of any sensor in the data center will indicate a malfunctioning tire sensor.
Remove the tire from the rim, then replace the faulty sensor with a new one. Next is to reinstall the tire and reprogram all your sensors again.
What about a faulty TPMS module?
If all your sensors’ readings are on-point and look like they are in good working condition, the only possible option is a faulty TPMS unit.
But just like in any other troubleshooting situation, when you reach the end of the troubleshooting chart and the only remaining option is to replace the ECM, I strongly suggest you start over and check everything all over again.
A broken central unit or module is rare, and such a diagnosis can quickly turn out as a costly mistake.
Final thoughts
To conclude, anybody working on TPMS systems needs to keep in mind and understand that tire pressure systems aren’t standardized like OBD and CAN buses are. Every car manufacturer still has its way of doing things.
Because TPMS is still relatively new, they are subject to new features being added. Also, new and more complicated relearn procedures and constant improvement.
Thus, always make sure to research and review how the system works on your car before fixing anything.
Aside from that, tire pressure sensor faults can easily be fixed with a bit of knowledge, good tools, and a lot of practice.
