Indirect TPMS (Tire Pressure Monitoring System)

Indirect TPMS (Tire Pressure Monitoring System) is a type of system that doesn’t use physical sensors inside the tires to directly measure air pressure. Instead, it relies on data from the vehicle’s ABS (Anti-lock Braking System) or wheel speed sensors to estimate tire pressure.

Here’s how it works:

Indirect TPMS tracks the rotational speed of each wheel. When a tire loses air, its radius shrinks, causing it to rotate faster than the other tires. The system detects these variations in speed and identifies which tire may have low pressure. Based on this data, it alerts the driver about a possible tire pressure issue.

Advantages of Indirect TPMS:

• Cost-effective: It is less expensive to install compared to direct TPMS, which requires physical sensors in each tire.
• No need for battery replacements: Since it uses existing vehicle sensors, there are no batteries in the tires, reducing the need for maintenance.

Disadvantages:

• Less precise: Indirect TPMS does not provide exact tire pressure readings; it only detects significant differences in tire pressure, which may be less accurate than a direct system.
• Influenced by vehicle dynamics: Indirect TPMS can sometimes give false alerts due to factors like the vehicle’s load or road conditions, which can affect wheel speed and lead to incorrect tire pressure warnings.

Overall, indirect TPMS is a more budget-friendly and simpler system compared to direct TPMS, but it comes with compromises in accuracy and dependability.