How to Reset Your Tire Pressure Light to Save Time and Money
Table of Contents
- Why Your Tire Pressure Light Comes On
- Checking the Recommended Tire Pressures
- When to Check and Adjust Tire Pressures
- Adjusting Pressures for All 4 Tires
- Don't Forget the Spare Tire Pressure
- How to Reset Tire Pressure Light
- Conclusion and Summary
Why Your Tire Pressure Light Comes On
The tire pressure monitoring system (TPMS) in modern vehicles is designed to alert drivers when there is an issue with tire pressure. The system consists of sensors attached to each wheel that constantly monitor air pressure levels. When pressure drops too low in one or more tires, the TPMS triggers the tire pressure warning light on the dashboard to inform the driver.
There are two main reasons why the tire pressure light illuminates - an actual tire pressure issue, or a TPMS sensor malfunction.
TPMS Sensor Monitors Tire Pressure
Each tire has a battery-powered TPMS sensor mounted inside behind the valve stem. The sensor measures air pressure and temperature, then transmits this data wirelessly to a receiver module in the vehicle. Values are compared to preset thresholds to determine if inflation is at recommended levels.
Incorrect Tire Pressure Triggers the Light
When measured pressure or temperature veers outside preset parametres in one or more tires, the TPMS determines this to be an issue and illuminates the tire pressure warning light. Low pressures could indicate a puncture, leak, or general deflation over time.
Checking the Recommended Tire Pressures
The vehicle manufacturer provides a reference placard indicating recommended cold inflation pressures for front, rear, and spare tires. This is usually located on the inside edge of the driver's door or door jamb. DO NOT guess at appropriate pressures - always refer to the placard.
Pressures should be checked with tires cold before driving for accurate readings. After driving, tires heat up and pressures increase which leads to false readings.
Note that recommended pressures account for variables like average load, handling, braking, suspension damping, and other factors. Following these pressures ensures ideal tire performance and safety.
When to Check and Adjust Tire Pressures
Check Before Driving When Cold
For consistent readings, tire pressures should always be measured before the vehicle has been driven, when tires are cold. Cold tires mean the vehicle has been stationary for 3 or more hours. Driving raises tire temperatures and consequently pressures. When hot, pressure could read 5-10 PSI higher than when cold. Adjusting pressures when hot could lead to dangerous under-inflation when cooled down.
Make Tire Pressure Your First Stop
If pressures need adjustment but you must drive somewhere first, make checking and filling tires the very first stop. Minimize driving distance and duration to keep tires as cold as possible for accurate adjustment.
Adjusting Pressures for All 4 Tires
Don't Skip Any Tires
It is critical to check and adjust (if needed) pressures for all four mounted tires, not just one or two showing issues. The TPMS compares readings from all four to determine irregularities. Skipping tires or only addressing low ones displayed by the TPMS can mean other borderline pressures go unnoticed. The light may then stay on or re-trigger soon after.
Don't Forget the Spare Tire Pressure
Most Spares Have TPMS Sensors
Surprisingly, many modern spare tires also contain TPMS sensors to monitor their pressure and temperature. The values transmit back to the vehicle just like the four mounted wheels. If the spare is under-inflated, even if not currently in use, it can cause the tire pressure warning light to engage on the dash.
Spare Tire Location Varies by Car
Depending on the vehicle, spare tires may be mounted externally under the chassis, inside the rear storage area, or even within a special compartment inside the floor. Consult the owner's manual to locate it. In certain models, mechanical cranking or electric motors may be required to lower the spare for access to the valve stem. Adjust pressure to recommended placard levels for the spare before raising it again.
How to Reset Tire Pressure Light
Drive Over 10 Minutes After Proper Inflation
Once all five tires have accurate cold pressures per the placard, the TPMS light should go off automatically within 5-10 minutes of driving above 25 mph. This allows all wheel sensors to take new readings confirming proper inflation, deactivate warning indicators, and clear any error codes.
Occasional Sensor Failure Requires Dealer Reset
If the light remains on even with accurate pressures, one or more TPMS sensors may have failed. Electronic diagnostics by a dealer can pinpoint faulty sensors for replacement under warranty. In rare cases dealers may also need to manually reset the TPMS computer using a diagnostic scan tool if it has locked faulty codes into memory.
Conclusion and Summary
Maintaining recommended cold tire pressures is critical for safety, handling, wear life and efficiency. The TPMS system provides an early alert when inflations deviate from ideal levels.
Addressing low pressures promptly when the warning light comes on, and periodically confirming adequate pressures even without indicators, ensures you get maximum mileage out of your tires with confidence.
FAQ
Q: Why did my tire pressure light come on suddenly?
A: The tire pressure light often comes on suddenly due to a drop in outside air temperatures affecting tire pressures. It indicates the pressures need adjustment.
Q: How do I check my recommended tire pressures?
A: You can find the recommended front, rear, and spare tire pressures listed on a label located on the inside of your driver's side door.
Q: Do I need tools to adjust tire pressures?
A: No special tools are needed. Use a standard tire pressure gauge and air compressor at a gas station or auto parts store to inflate your tires.
Q: How will I know when tire pressures are set correctly?
A: Set each tire's pressure according to the car manufacturer's recommendations listed on the tire placard. Recheck with a tire gauge to confirm proper inflation.
Q: Do I need to include my spare tire?
A: Yes, you need to check and adjust your spare tire pressure as well since many spares have TPMS sensors that could trigger the light.
Q: Where is my spare tire located?
A: Spare tire placement varies - check under the trunk carpet or cargo area, or sometimes under the rear bumper. Refer to your owner's manual if unsure.
Q: Why won't my tire pressure light turn off?
A: If tire pressures are set correctly and the light remains on, an occasional TPMS sensor failure may require a dealer reset. This is uncommon, so first ensure all 5 tires have proper inflation.
Q: Do tire pressures change in hot weather?
A: Yes, tire pressures increase as outside temperatures rise. Check pressures again during summer months to ensure they remain at recommended levels.
Q: How long should I drive to reset the light?
A: After properly setting tire pressures, a drive of 10+ minutes allows the TPMS system to automatically reset and turn the warning light off.
Q: Will TPMS sensors need replacement over time?
A: The tire pressure monitoring sensors have a typical lifespan of about 10 years before possibly needing dealer replacement.