Tire Pressure Sensor Fault & How to Fix
You’ve probably experienced it before: You’re driving and suddenly a “Tire Pressure Sensor Error” message or warning light appears in your instrument cluster. But what exactly does this mean, how do you fix it, and how much does it cost?
What is a tire pressure sensor?
Tire pressure sensors are small computers located inside each tire. They are designed to warn drivers when tires are low on air pressure. Tire pressure sensors (TPMS for short) have been mandatory for all vehicles in the United States since 2007. There are two common types of tire pressure sensors:
1. The first is the valve type, where the sensor and the valve stem are one piece.
2. The second is the band sensor, where the sensor is attached to the inside of the rim by a metal band. Both sensors will activate a light on the dashboard if the air pressure reading is lower than it should be, alerting the driver to low tire pressure.
What are the tire pressure sensor error messages? When the tire pressure sensor detects a low tire pressure issue, it sends a signal to the car’s computer and a light turns on on the dashboard.
This light is usually bright yellow and looks like an exclamation point (!) in a U-shaped symbol. It’s a warning to the driver to check their tires because they may be flat or underinflated.
Can I still drive my car? Driving with underinflated tires can cause your vehicle to pull in one direction or another, depending on which tire is underinflated. This can cause the driver to lose control of the vehicle and is extremely dangerous.
Driving with a flat tire can at the very least cause uneven tire wear and at worst damage the structural integrity of the tire, especially the sidewall. This can eventually cause the tire to burst upon re-inflation. If you drive with a completely flat tire, this damage will require a tire change.
If you’ve verified that all your tires have sufficient air pressure, then you simply have a faulty sensor. At this point, the driver’s only concern is the bright light shining from the dashboard.
The driver should pay close attention to the tire pressure, as a failed sensor will not show the actual pressure. For security reasons, this should be fixed as soon as possible.
Other types of sensor errors
If your car displays the message “Tire Pressure Sensor Error”, it is not necessarily due to tire pressure being too low. There are several types of errors that can cause this warning:
1. Communication Error – The sensor may be working fine but not communicating properly with the car’s computer. This could be due to electrical interference or a system error.
2. Physical Damage – Driving over a pothole or a curb can damage sensitive components in the sensor. Even a small impact can cause problems.
3. Battery Failure – TPMS sensors have their own batteries that typically last for 5-10 years. If these batteries run out, the sensors will no longer be able to send a signal.
4. Corrosion – Over time, road salt, moisture, and other environmental factors can corrode the sensor and impair its functionality.
5. Programming Issues – If you’ve recently changed your wheels or tires, the sensor may not have been properly reprogrammed, causing communication errors.
6. Faulty Sensor – The sensor itself may simply be broken and need to be replaced.
While these are common types of sensor failures, be aware that there are other reasons why your TPMS light may come on even if your tires are properly inflated.
Troubleshooting Steps
Before consulting a mechanic, there are a few things you can try to resolve your tire pressure sensor error. Who knows? Maybe this will save you a trip to the workshop.
Step 1 – Check your tire pressure
I know, I know. It sounds obvious, but start here. Use a trusty tire pressure gauge to check all four tires, including the spare if your vehicle is equipped with a sensor. Sometimes the simplest solution is the right one.
Even 5 PSI below the manufacturer’s recommended pressure can cause a warning light to come on on your dashboard. You can find the manufacturer’s recommended pressure in your owner’s manual or on a sticker on the driver’s door jamb.
Step 2 – Go for a short drive
Sometimes the sensor just needs a little wake-up call. Get in your car and take a quick spin around the block. This movement will help reset the sensor and start communicating properly again.
Step 3 – Think about recent maintenance
Have you changed your tires recently? Your sensor may need to be reprogrammed. On some vehicles, this happens automatically after a while, while on others it must be done by a technician. Contact a tire/service center and explain the situation. They may recommend driving a little longer to “relearn” the sensor, or simply ask you to drive back to the sensor so a technician can take a look.
Step 4 – Check the wheels for damage
Look closely at the wheels. Any visible damage to the rims could affect the sensor. At the same time, check the valve stems.
Step 5 – Try a manual reset
Some vehicles have a TPMS reset button. Consult your owner’s manual to find out where it is (often under the steering wheel) and how to properly reset it. This will likely fix the error.
Step 6 – Check the battery
If your car has been sitting for a while, a weak battery can cause a sensor error. Make sure your car’s battery is fully charged. If these steps don’t fix the problem, you’ll need to contact a professional. They have special tools that can communicate directly with the TPMS sensors to pinpoint the exact problem.
To Replace or Not to Replace
best automotive diagnostic scanner
If checking and adjusting the tire pressure to within the proper specs does not remedy the problem, chances are good replacing the tire pressure sensor is necessary.
While having an automotive scan tool will let you diagnose the problem yourself, you can always have a local tire or repair shop perform a scan to quickly identify which sensor has failed. The battery life of these sensors typically ranges from 5 to 10 years.
TPMS Sensor Replacement Procedure
In order to replace a failed tire pressure sensor, the wheel with the bad sensor must have the tire dismounted. Once the tire is off the rim, the old sensor can be removed and the new one installed.
After the new sensor is put in the rim, the tire will be remounted and inflated. Then comes reprogramming so the car’s computer will recognize it.
Since most car owners don’t have the capability to dismount and remount a tire, a trip to the local tire shop is necessary. Fortunately, the process isn’t very expensive and you can usually purchase the TPMS sensor cheaper on your own to save some money.
Sensing/Reprogramming the Sensor
The reprogramming process varies for each vehicle’s make and model. Some cars require a certain amount of mileage to be put on the new sensor for the computer to recognize it, usually just a couple miles.
Other vehicles must be reprogrammed using the same scanner that found the bad one. The scanner programs the sensor’s signal to the car’s computer so the two can communicate. Without this, the dash light will stay illuminated because the computer can’t read the new sensor, making reprogramming a crucial part of the replacement.
