Like any piece of automotive technology, tire pressure sensors can sometimes fail. Diagnosing these faults is essential to keeping your vehicle in top shape. In this step-by-step guide, we’ll walk you through how to diagnose tire pressure sensor faults, provide real-world examples, and effective solutions to restore your TPMS to full functionality.
Before you can figure out how to diagnose a tire pressure sensor fault, it’s important to understand how tire pressure sensors work. TPMS generally come in two types:
Direct TPMS: Each tire has a sensor that directly measures tire pressure and sends this data to the vehicle’s onboard computer.
Indirect TPMS: These sensors use data from the vehicle’s ABS (anti-lock braking system) to detect changes in tire rotation speed, which can indicate a drop in pressure.
Most modern vehicles use direct TPMS, which provides a more accurate reading. These sensors are usually located inside the tire, attached to the valve stem. They measure tire pressure and communicate with the vehicle’s central system, which triggers a warning light on your dashboard when the pressure drops below a certain threshold.
Identify the symptoms of a tire pressure sensor fault
Keep in mind that a faulty tire pressure sensor often exhibits specific symptoms. And understanding these symptoms will be the first step in diagnosing a fault.
First, the TPMS warning light stays on: If the warning light stays on after you check the tire pressure, it could indicate a sensor problem.
Second, flashing TPMS light: A flashing TPMS light usually indicates that there is a fault with the system, not just low tire pressure.
Another is erratic readings or no readings: Some systems may display incorrect tire pressure readings or fail to show any pressure at all, which could indicate a sensor fault.
Lastly, constant tire pressure warning: If you continue to receive warnings about low tire pressure even after your tires are properly inflated, the sensor may be faulty.
For example, let’s say you’re driving and you notice that the TPMS light is on. You manually check your tire pressure and all tires are at the correct PSI. However, the warning light remains on. This could indicate a sensor fault, and it’s time to diagnose it further.
Step-by-Step Guide to Diagnosing Tire Pressure Sensor Malfunctions
Step 1: Check Tire Pressure Manually
The first thing you should do if the TPMS light is on is to manually check the tire pressure with a gauge. Even if you suspect a sensor problem, it’s important to rule out low tire pressure as the cause.
Action: Use a reliable tire pressure gauge to check all four tires. Compare the readings to the recommended tire pressures listed in your owner’s manual or on the tire placard located on the driver’s side door jamb.
However, if all tires are properly inflated and the TPMS light is on, move on to the next step.
Step 2: Use a Diagnostic Tool or OBD-II Scanner
Most modern vehicles can be diagnosed with an OBD-II (On-Board Diagnostics) scanner. This tool can read error codes from your vehicle’s computer system, which will help identify any issues with the TPMS.
Action: Plug the OBD-II scanner into the vehicle’s diagnostic port, usually located under the dashboard near the steering column. Follow the scanner’s instructions to retrieve any error codes related to the TPMS system.
Error codes such as C1000 (TPMS malfunction) or C1034 (sensor failure) are common indicators of a sensor problem.
Step 3: Visually inspect the tire pressure sensors
If the OBD-II scan indicates a sensor problem, the next step is to physically inspect the sensors. A damaged or worn sensor is often the root cause of the problem.
Action: To inspect the sensors, you will need to remove the tire from the wheel. This is usually done by a mechanic, as it involves deflating the tire and removing it from the rim. Look for any visible damage to the sensor, valve stem, or wiring.
Remember: A cracked or worn sensor may need to be replaced. If there is no visible damage, the problem may lie in the sensor’s internal battery or wiring.
Step 4: Check the sensor battery
Tire pressure sensors are powered by small batteries that typically last between 5-10 years. Over time, these batteries can lose charge, causing the sensor to fail.
Action: If you have a sensor integrated into the valve stem, replacing the battery itself can be difficult. In most cases, you will need to replace the entire sensor. However, some sensors are designed with replaceable batteries, which can be swapped out if necessary.
Step 5: Reset the TPMS System
Once the faulty sensor has been identified and repaired or replaced, it may be necessary to reset the TPMS system to recalibrate the sensor.
Action: Refer to your vehicle manual for instructions on resetting the TPMS system. In many cases, you can do this by turning the ignition key to the “on” position and holding the TPMS reset button until the light flashes and then turns off.
Note: After the system is reset, the TPMS light should go off, and the vehicle should display the correct tire pressure reading.
Step 6: Test the System
After replacing the sensor and resetting the system, take the vehicle for a short drive to test the TPMS. During the drive, check to see if the warning light stays off and the pressure reading matches the manual gauge reading.
Action: If the light comes back on or the reading is still not correct, there may be a problem with the wiring or another sensor.
If everything works properly after testing, your problem is solved.
When to Seek Professional Help
While the steps above can help diagnose and fix many tire pressure sensor faults, some problems may require professional assistance. If you are unable to identify the fault, or if you are not comfortable handling tire dismounting and sensor replacement, it is best to visit a certified mechanic or tire shop.
Professionals have specialized tools and expertise to diagnose complex TPMS problems, including sensor synchronization issues or faulty communication with the vehicle’s onboard computer.
How to Prevent Tire Pressure Sensor Failures
Check your tire pressure regularly: Use a manual gauge to check your tire pressure monthly to make sure the sensors are working properly.
Avoid extreme temperatures: Extreme heat or cold can affect the performance of TPMS sensors. Try to park your car in a shaded area during hot weather and avoid driving in freezing conditions for long periods of time.
Replace sensors on time: Since tire pressure sensors typically last 5-10 years, be sure to replace them as needed, especially if you notice any problems with the system.
Conclusion
By following these guidelines, you can effectively identify the source of the problem and either fix it yourself or seek professional help if necessary. Ensuring that your TPMS is working properly is essential for your safety, fuel efficiency, and tire longevity.
Remember, while you can diagnose and fix sensor errors yourself, don’t hesitate to consult a mechanic if you feel unsure or uncomfortable with the process.