Modern Auto MechanicsModern Auto Mechanics

By Bill Kuhl http://www.scienceguy.org Special Thanks Dave MacLeod

 Increasingly modern vehicles are a marriage of electronics and mechanical components. Special equipment and skills are needed to keep these vehicles operating in top shape. Like almost any profession continuing education will be necessary to keep current with new technologies. 

Vehicle Computer

Modern automobiles may show problems through fault lights that correspond to fault codes that require electronic equipment to decipher. 

Even with the proper test equipment like the Snap-on MODIS device pictured above the problem can be complicated to diagnose as one problem can generate multiple codes.  

Newer vehicles have plug for diagnostic devices.

Proper adapter is needed to plug diagnostic device.

The Snap-on MODIS device can read engine fault codes and many types of data. It could even be connected to the vehicle when driven monitoring air, brakes, etc. 

It is very important that students are comfortable reading graphs and be able to interpret the data because the scales on the graphs are ever changing. 

Sensors communicate with the vehicle computer.

Quote from article by Dale J. Long website:http://technologyinterface.nmsu.edu/winter99/manufacturing/long/long.html“Automobile sensors can be classified into three basic areas: drive-train and vehicle control, driver safety/comfort/information and emissions. They are used to monitor temperature, gases, voltages/currents, vacuum and torque to name a few. Twenty years ago, the typical automobile had approximately five sensors. Today, over fifty sensors are used to control everything from braking to the fuel delivery system.”  Dale J. Long

The carburetor used on vehicles before fuel injection.

Computer technology has enabled fuel injection systems to almost completely replace the carburetor system used for many years before that.By processing the data from a variety of sensors, the fuel-air mixture can be more precisely controlled for a better operating engine. Engines should start better, run smoother, are more fuel efficient and less polluting.

Fuel injector

Electronics in newer cars have replaced the mechanicals parts that wear out in older cars that had points and a distributor. Before the new electronic ignition, cars would often require points to be adjusted or replaced every 10,000 miles or so.  Electronic ignition provides more accurate spark timing which improves the combustion and emissions.

Distributor and coil seen in this picture.

Relay

Points

Only balancing tires is not enough to ensure that there are not additional issues with the tires that could be causing steering problems or causing the car to pull when going driving down the road. Newer testing equipment such as the StraightTrak Road Force Measurement System in the pictures above can check for tire conditions such as “conicity”. Conicity can be a manufacturing glitch where the tire’s tread has cured in a slight cone shape.

The modern method for checking the alignment of an automobile utilizes electronic camera type sensors and a computer to give readings for such as camber, toe, and caster. Newer equipments sets up quicker which allow the service provider to charge less yet make more money because of the faster time for the alignment.

Auto mechanics students will increasingly need to be able to work on radically different types of automotive technology now and in the future.

The pictures below are of a transaxle from a Toyota Prius hybrid. Hybrid cars unite a fuel powered engine and an electric motor to increase fuel efficiency and reduce emissions. This system is rather complex in that various techniques are employed to increase efficiency such as charging batteries while braking, turning off the engine while stopped, and assisting the power to the wheels with electric power.