Tire Pressure Monitoring System (TPMS) has two main types based on how it works, that is direct and indirect TPMS. Of course, direct vs indirect TPMS has its own comparisons and differences.
The obvious difference between direct vs indirect TPMS in how it works is that direct TPSM sends real-time sensors while indirect TPMS is calculated by using ABS (Anti-lock Braking System) and ESP ESP (Electronic Stability Program) first.
This article will inform you about direct vs indirect TPMS from the difference in how it works and the comparison between the two.
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Table of Contents
How Direct vs Indirect TPMS Works
There are two main types of Tire Pressure Monitoring System based on how it works:
Direct TPSM
Direct TPMS uses pressure sensors mounted on each tire to measure air pressure directly.
It sends pressure and temperature data to the control unit in the vehicle. If there is a significant change, the system will give a warning.
Indirect TPSM
Indirect TPMS does not measure air pressure directly. Instead, it uses wheel speed sensors integrated with the vehicle’s ABS to monitor the difference in rotation speed between the tires.
If one tire rotates faster than the other, this could be an indication of low pressure, and the system will give a warning.
The Differences of Direct vs Indirect TPMS
In general, the difference between the two types of TPMS is that direct TPMS obtains pressure data directly from the tires, while indirect TPMS estimates tire pressure. Here are the differences of direct vs indirect TPMS:
Direct TPSM
- Uses a special sensor installed inside the tire
- Obtain tire pressure data in real-time
- More accurate as it relies on direct calculation of tire pressure
- More expensive and requires intensive maintenance
Indirect TPSM
- Uses wheel speed sensors from the ABS to estimate tire pressure
- More cost-effective and low-maintenance
- Less accurate as it is affected by factors such as tire wear, load, or road conditions
- May become inaccurate if you buy larger or smaller tires
The Comparison of Direct vs Indirect TPMS
Direct TPMS employments pressure sensors in each tire, whereas indirect TPMS employments wheel speed sensors. Here is the comparison of direct vs indirect TPMS:
| Comparison | Direct TPMS | Indirect TPMS |
| How it works | Pressure sensors in each tire monitor pressure levels | Wheel speed sensors measure how fast tires are rotating |
| Accuracy | More accurate, usually within 1 psi | Less accurate, may not detect pressure loss in all conditions |
| Maintenance | Susceptible to damage during mounting/demounting | Requires less programming and maintenance |
| Cost | May be more expensive than indirect TPMS | May be less expensive than direct TPMS |
That’s the differences and the comparison of TPMS that you must know. By knowing the comparison of direct vs indirect TPMS, hopefully, that can help you to choose the right system for your vehicle.
