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CZroe

Lifer
Jun 24, 2001
23,637
633
126
Direct TPMS doesn't interface with the ABS System at all.

Indirect TPMS has no sensor in the wheel and the low pressure lamp is triggered by the different rotational speed of the low tires pressure. It will be faster than a properly inflated tire.


Direct TPMS uses a sensor mounted in the wheel to measure air pressure in each tire. When air pressure drops 25% below the manufacturer’s recommended level, the sensor transmits that information to your car’s computer system and triggers your dashboard indicator light.


Indirect TPMS works with your car’s Antilock Braking System’s (ABS) wheel speed sensors. If a tire’s pressure is low, it will roll at a different wheel speed than the other tires. This information is detected by your car’s computer system, which triggers the dashboard indicator light.
Yeah, but do they continue operating the ABS and other traction control functions when they detect a low pressure condition? I've heard that the computer can disable ABS and/or traction control with a TPMS condition.
 
Last edited:

pcgeek11

Lifer
Jun 12, 2005
17,120
1,602
126
Yeah, but do they continue operating the ABS and other traction control functions when they detect a low pressure condition? I've heard that the computer can disable ABS if and/or traction control with a TPMS condition.

All the modern vehicles that I am familiar with will continue to operate the ABS System with a TPMS Light as long as the pressure is not actually low. As many people I know have been driving around with a TPMS Light on for years and the ABS Systems and Traction Control still work just fine. I work for a major automotive manufacturer supplier...

Now for the facts on all modern Direct TPMS and 4 Channel ABS Systems:

The ABS System uses a speed sensor on each wheel to feed rotation data to the ABS ECU (Computer).

When a tire has a valid TPMS Light due to a low tire pressure that tire will rotate at a different speed as that tire will be a smaller diameter than the other three tires.

The ABS System when it detects that a wheel is rotating at a different speed than the other three that Will Trigger an ABS and TRAC warning Light and ABS and Traction control will be disabled. Worst case you will have regular brakes. The ABS and Traction faults are triggered by the speed sensor Not the TPMS.

A failed TPMS Sensor will not trigger an ABS and TRAC warning light as long as the tire is not low on pressure. You could remove the TPMS Sensors and throw them in the garbage and it would not effect the ABS or Traction Control on a Direct System.

I hope this clears things up.
 
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