Understanding the Front/Rear Cross Traffic Systems

Understanding the Front/Rear Cross Traffic Systems

A key part of being able to diagnose a problem with Advanced Driver Assistance Systems (ADAS) is understanding how the system works. Knowing what is happening inside the system will help you properly diagnose why the system may be failing. This will prevent replacing parts that are not causing the system issue. Let’s take a look at the inner workings of a front/rear cross traffic system.

The rear cross traffic system uses the same sensors in the rear as a blind spot detection system. Radar sensors in the rear of the vehicle are used to detect an approaching vehicle or object. These sensors are normally behind the rear bumper on each side. However, there are some instances where the sensor is in a different location, such as in the tail light or in the quarter panel behind the bumper cover.

The front cross traffic system uses radar sensors similar to rear cross traffic to detect an oncoming threat. These sensors are located behind the front bumper. There are also systems that use cameras on each side of the front bumper cover to view the intersection that is being approached.

Radar sensors work by sending radio waves that are reflected off of objects. The time it takes for the radio wave to return indicate how far away the object is, how big the object is, and what direction the object is traveling.

Sometimes, the front/rear cross traffic system uses some of the same methods as blind spot detection to alert the driver of an approaching threat. The front/rear cross traffic system may use indicators on the mirrors or a message on the infotainment center or driver information center. Normally, it is accompanied by a warning sound or chime.

Generally, the radar sensors are set up as a master module and slave module. The slave module communicates to the master module, which communicates to other systems. If the slave module detects an object, the slave module will tell the master module that it sees an object. The master module, generally, will then talk to a different module to issue an alert.

Understanding how the systems function can shorten diagnostic times. Knowing what part of the system to test will help prevent installing parts that don’t actually fix the problem.