Causes of Electrical & Electronic Automotive Problems

Autosphere » Mechanical » Causes of Electrical & Electronic Automotive Problems
The complexity of electrical and electronic systems can lead to all sorts of problems, the origin of which may appear mysterious.
 Photo ShutterStock
Billy Thomas, Trainer at Uni-Select, says that several separate systems are working together, making diagnosis even more complex. Photo Uni-Select

With the explosion of electronic accessories and equipment in today’s cars, diagnosing problems becomes a science.

“Fortunately, electrical and electronic problems like this do not happen every day,” says Uni-Select’s Billy Thomas, an expert trainer. However, with the proliferation of comfort and safety accessories, there are some confusing situations. Finding the source of the problem is a matter of investigation.

As this expert mentions, several control modules are connected in complex systems. Discerning between a problem with a mechanical part, a controller or a module that picks up an error signal is part of the diagnostic process. He specifies that sometimes it can be corrosion affecting a sensor or its wiring. For example, the seat adjustment control module is sometimes located on the floor, under the carpet, and is exposed to moisture.

Strange problems

“We also have some surprises and odd problems,” Thomas says. “In one particular case, a wiper blade on the rear hatch was not positioned correctly. It sent the activity message even though the ignition key had been removed. As a result, the battery was completely drained.”

He notes, however, that the integrity of the control module is rarely in question. Rather, it is a question of order conflicts between components whose important level of collaboration cannot be guessed at times. This is particularly true of ABS braking systems linked to the engine speed control module, which work together to stabilize the vehicle in case of loss of grip.

Vast-Auto Academy trainer Wilson Almeida is well aware of these issues where electronics and electricity can collide. “You can’t just replace an accessory or an engine when it fails,” he says. “You have to understand the systems and get to the source. The technician, before even opening his toolbox, must analyze the diagnostic chart. This is not always easy for French speakers, as this information is usually in English. That being said, on the diagnostic and repair platform you will find descriptions and operations of electrical and electronic systems. I stress the importance of training.”

Wilson Almeida, Director of Training for the Vast Academy, focuses on developing technical skills. Photo Autosphere.ca

Understanding the systems

Understanding how systems work is essential, he insists. He illustrates this by talking about a Chevrolet Volt that simply decided to stop working. “It was a situation that left everyone confused, including the dealer. Yet, once I got there, it was easy to realize that all this car needed before it could be driven again was a module reprogramming.”

For Almeida, shops need to push their expertise further in anticipation of increasingly complex vehicles. Let’s think about electric vehicles, or more commonly, about those cars equipped with advanced driving assistance systems that will further confuse the issue.

Michel Julien, a well-known specialist in electronic diagnostics, points out a very common source of electronic problems. “Sensors, probes and modules are very sensitive to power supply variations. I would say that 70% of the sometimes strange anomalies are related to the battery or grounding. Corroded terminals on the battery or a ground that is not properly positioned or connected to a surface that is not clean can cause error codes or affect the operation of electronic components. A transmission that shifts poorly can simply be explained by battery terminals covered in verdigris.”

Trainer Michel Julien mentions that many anomalies on accessories and sensors are related to their poor grounding. Photo Michel Beaunoyer

According to him, the infuriating intermittent problems stem from these reasons. Touring the grounding of problematic parts is recommended. He mentions in passing that there are about 50 electronic and electrical components with a ground connection, mainly on the chassis, on a modern vehicle. Like his colleagues, Mr. Julien reminds us of the importance of understanding systems, consulting charters and performing electronic diagnostics before considering replacing a part.

How not to be of service

Finally, Julien mentions another factor that can contribute to a whole family of problems: replacing a 600-amp battery with a beefier 900-amp version. “We want to do a favor for a customer who wants plenty of power, but in reality, it’s a bad choice that will cause a lot of problems,” he says. “The battery does not match the vehicle’s charging system and will never charge to 100 percent. The gradual drop in voltage will come in and create a bunch of electronic problems, starting with the accessories that require the most power.”

In short, the constant introduction of accessories and advanced technologies to improve the performance, safety and comfort of modern cars means that the technicians in our workshops have to understand very complex systems.


Popular Posts



10janAll Day31marASE Winter Testing Registration Now Available

26febAll Day283 Day Hybrid / EV Training Program


11marAll Day15Mastering The Art of Diagnosis Level One