ASE Suspension and Steering (A4) Practice Test

The TPMS (Tire Pressure Monitoring System) light activates primarily to alert the driver of low tire pressure in one or more tires. When the air pressure in a tire drops below the recommended level, the TPMS sensor detects this change and triggers the warning light on the dashboard. Maintaining proper tire pressure is crucial for vehicle safety, fuel efficiency, and tire longevity; therefore, the system is designed to provide immediate notification of any issues.

Regarding the other choices, while worn brake pads and misaligned wheels are important for vehicle performance and can lead to other warning indicators or issues, they do not directly relate to tire pressure monitoring. Having all tires correctly inflated would mean the TPMS light should not be activated, as proper inflation would not trigger the system. Thus, only low pressure in one tire would specifically cause the TPMS light to activate.