Electronic diagnostics have become a critical part of automotive service, essential to identifying the true source of problems that would otherwise be nearly impossible to pinpoint.

A modern-day scenario: a vehicle that won’t start because of a faulty camera located beneath the windshield. “To make things even more confusing, the scan tool tells me the problem is with the transmission,” says instructor Pierre Henry of L’Atelier branché, who experienced the situation first-hand.

He’s seen it all. Over the years, he’s also noticed how much more complex in-vehicle communication networks have become. “A Silverado pickup, for instance, includes 40 electronic modules that communicate across 15 shared data networks. So if there’s a short circuit somewhere on one network, everything connected to it goes down. That triggers a fault code when you scan the system. The tool will show a communication problem on that network, and it’s up to the technician to trace it methodically.”

A corroded wire, a faulty sensor, or a module that needs updating could all be behind abnormal vehicle behaviour or a feature that suddenly stops working. According to every expert interviewed for this article, diagnostics have evolved rapidly in recent years. Today’s repair shops must be able to handle both electrical and electronic troubleshooting if they want to remain competitive. Connecting a scan tool gives access to over 2,000 paths running through the communication networks, checking for proper operation.

All Vehicles

“You’ll find electronic issues in every kind of car these days, even entry-level models,” says Wilson Almeida, Director of the Vast-Auto Distribution Academy. “In modern repair and maintenance, the computer has replaced the screwdriver. You have to learn how to read and interpret wiring diagrams. The old approach of swapping out parts just because it worked before is no longer acceptable.”

Sometimes, it’s hard to explain this to customers who walk in with what they’ve learned from YouTube. “Before we can fix anything, we need to diagnose it properly. That’s why trained and properly equipped technicians are essential, especially when you realize that 70 percent of our techs don’t hold a professional mechanic’s diploma,” Almeida explains. “And it’s just as important that front-counter staff understand what’s going on, because they’re the ones who need to educate the customer.”

Tracing the Root Cause

The aftermarket is facing a major challenge. Every year, vehicles rolling into the service bay are more and more sophisticated. “That’s why my fall training tour will focus, in part, on communication protocols and vehicle data networks,” says Billy Thomas, Training Specialist at Bumper to Bumper. “I agree, electronic diagnostics aren’t easy. But these days, you can’t do a single thing on a car without first scanning it to assess its health, and then following that up with the right diagnostic path to make the proper repair.”

Thomas also stresses the importance of customer education. “The tech’s instincts need to change. Electronic diagnostics are now a careful investigative process,” he explains. “Customers have to understand that identifying the root of the problem takes time, but it’s still cheaper than replacing the wrong parts.”

Preventing Nasty Surprises

“Technology is giving us some real challenges,” says Al Kozun, Technical Trainer for the NAPA repair network. “Take keyless fobs, which now look more like credit cards. They work by sending a signal to an antenna located inside the vehicle. But what happens when that antenna corrodes or fails altogether? How do you unlock the car without a physical key if the signal can’t be received?”

For Kozun, the only way for independent shops to keep up is by following a clear diagnostic plan. Step one is having access to a current oscilloscope and an up-to-date scan tool. But reading the data isn’t enough on its own, it just points the technician toward the tests that need to be done.

Step two is gathering information from both the customer and the vehicle. “After that, follow the steps. Review the technical service bulletins. Understand the paths involved and the specific tests that need to be run—in the right order—to get to the solution,” Kozun says.

A Natural Drive to Fix

Fortunately, he adds, professional mechanics are wired to fix things. “Thanks to social media, we’re seeing online communities of experts grow everywhere. Techs are constantly sharing problems and solutions with each other,” says the trainer. “Solving problems is just part of a mechanic’s DNA.”

He recommends scanning every vehicle as soon as it enters the shop, and sharing a health report with the customer. “With the increase in electrical and electronic issues, we need to bring customers into the conversation right from the start. That’s how you build trust—so when it comes time to charge for diagnostic labour, they understand what they’re paying for,” Kozun concludes