Today's modern vehicles rely heavily on a variety of electronic controls...some I'm sure you're already familiar with.  Engine management, antilock braking, and vehicle stability just to name a few.  But are you ready for active cruise control utilizing multiple radar sensors, electronic parking assist, antifogging detection and more?  A recent OE company president predicts an average increase of 15-20% per year in the use of electronic systems to add to customer convenience and safety, and even take the place of many systems operated by mechanical means now...like braking and steering control.

The technician who is ready for this challenge will find that these three things become his best diagnostic friends...a good scan tool (see related page here at AutoServiceTech), a good DVOM (Digital Volt-Ohm Meter) and a good DSO (Digital Storage Oscilloscope).  This section of AutoServiceTech is all about the last on the last...the DSO.

The use of oscilloscopes is nothing new to automotive diagnostics.  Techs have used them for years to inspect the ignition system for proper operation.  But this tool can do so much more if you know how to unlock the power of it.  Here, we will share a number of topics on choosing a scope, using a scope, and specifics on how to test a variety of electrical systems with a scope.

A good scan tool will tell you what a module "sees" and allows you to issue certain commands to the module to see if it can carry out its duties.  But it doesn't tell you if what it "sees" is really what it is being told.  And that's one area a scope shines in.

Inspecting a modern ignition system for proper function without a scope is a matter of educated guesswork.  Using a scope quickly tells you exactly how the system is working, and what has failed.

Even checking the mechanical integrity of the engine itself can be done in minutes with a good scope and a few dedicated probes.  For example, how would you like to get an idea of engine compression on all cylinders in roughly 5 minutes?  You can't remove the plugs on a modern 4 cylinder that fast...let alone all the cylinders on some transverse V6 designs.  Many of these require removal of the intake upper manifold in order to even see where the plugs are.

And so much more...

So, bookmark this page and check back often.  This area is under a constant state of construction and we actively seek your feedback.  Like what you've seen?  Have a topic you'd like to see addressed?  Let us know.  We'd love to hear from you.

Enjoy!