Why Does the Tire Pressure Warning Light Stay On When Tire Pressure is Normal?
3 Answers
When a vehicle's tire pressure is normal but the tire pressure warning light remains illuminated, it is typically because the tire pressure was previously too low. Although the pressure has been replenished, the tire pressure reset procedure was not performed, causing the tire pressure monitoring system to retain the original fault code. As a result, the warning light stays on. Additionally, a malfunctioning tire pressure sensor or system failure can also trigger the warning light despite normal tire pressure. Below are relevant explanations: 1. When tire pressure is too high or too low: The tire pressure warning light activates due to excessive or insufficient tire pressure. Check for punctures, damage, or air leaks in the tires. Use a tire pressure gauge to measure the pressure of each tire. Generally, the recommended pressure range for drive tires is 2.3 to 2.7 bar, while non-drive tires should maintain 2.2 to 2.5 bar. If all tire pressures are normal, attempt a tire pressure reset. 2. Resetting tire pressure: Press and hold the tire pressure monitoring button (located on the right side in front of the gearshift lever) for approximately five seconds to reset. For models without a dedicated SET button for tire pressure reset, the procedure can usually be performed through the settings option in the central display. Some vehicle models may allow resetting tire pressure and related maintenance data via the service records menu.
I've encountered this phenomenon several times. When driving my own car, the tire pressure measured with a gauge is normal, but the indicator light on the dashboard remains on. The possible reasons could be a malfunction in the tire pressure sensor. When the sensor's battery is depleted, it may send false signals, making the system think the tire pressure is low. Or, the sensor might be dirty or aged, loosening on bumpy roads and affecting its accuracy. Also, significant weather changes, such as from hot to cold, can cause the air to contract, leading the sensor to misjudge. Last time I went to a professional shop, the mechanic said that if the tires were recently replaced and the system wasn't reset, it could also trigger a false alarm. It's recommended to first recheck the tire pressure with a portable gauge to confirm it's correct, then try restarting the vehicle's system or removing and reinserting the fuse for a few seconds. If the light is still on, it's best to visit a repair shop as soon as possible to read the fault codes with an OBD scanner. Remember, ignoring this light might hide potential tire hazards, affecting driving safety, especially during long-distance trips. Regularly checking the sensor's lifespan during maintenance can prevent such issues.
As someone who frequently helps with car repairs, I've seen many such cases. The tire pressure warning light coming on despite normal pressure is often due to sensor issues. The sensor batteries can deplete after a few years, preventing proper data transmission; or the sensors may be damaged, corroded by moisture inside the tire. Wiring faults are another major cause, such as loose or short-circuited connections in the wheel, interrupting signal transmission. There's also the system calibration issue—when you install new tires, if the monitoring system isn't reset, it will continue to alert based on old parameters. In cold weather, changes in air density can also cause sensor misreadings. In practice, I recommend drivers first manually check all tire pressures with a gauge. If pressures are consistent and correct, inspect tires for puncture leaks. If none are found, consider professional diagnostic equipment at a shop. Address it early to avoid accidents—after all, the tire pressure system is a critical safety component that can provide early warnings of real problems.
