Diagnosing Vehicle Communication Issues

Learn about a quick and easy way to test a vehicle's communication network and get to the bottom of no-communication problems efficiently.

Diagnosing vehicle communication issues can be a challenge on some of the newer models in today’s market.

It can be hard to know where to start given the amount of different types of networks that these vehicles operate with.

But there are ways to get to the bottom of issues efficiently using the Guided Component Tests provided by the diagnostic software and scan tools from Snap-on. 

BMW Flex Ray Bus system

Let’s use a 2013 BWM X5 as an example. That vehicle has a Flex Ray Bus network, which is much faster than CAN (Controller Area Network) systems.

A built-in Guided Component Test will help you to use your lab scope to check whether the vehicle is communicating as it should do.

Once you have hooked up your tool and allowed it to automatically ID your vehicle, go to Fuel Injection System in order to test the communication networks then choose Flex Ray Bus.

This will help you to run a signature test, and before you do so the system will also give you all of the information you need so that you can correctly connect all of your test leads.

When that is done, you can also see a clear picture of what the signature is supposed to look like and also some voltage ranges so that you know what to look out for.

Hit the View Meter button to show the signal coming from the vehicle and compare it to the data shown in the test.

If there were any problems, such as a short to ground or short to five-volt power, they would be shown up pretty quickly on the signal and would stand out given that Flex Ray Bus networks normally operate within the five-to-zero volt range.

This particular Guided Component Test gives you a quick and easy way to diagnose no-communication issues on modern network systems.

The Snap-on diagnostic software includes Component Test Meter coverage for hundreds of vehicles and systems across 29 manufacturers.

Learn more about how the software can help prepare you to deal with even more of the challenges provided by today’s vehicles – meaning you don’t have to say no to a job.

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Date posted: 17 July 2019

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