Building the Right Diagnostic Routine

The ever-developing technology on modern vehicles means that having a solid diagnostic routine can make you more efficient in the workshop.

But what does having a solid diagnostic routine consist of? What are the steps you should be taking when you’re presented with a problematic car?

This handy guide from Snap-on®, manufacturer of industry-leading car diagnostic tools and software, talks you through what you need to know – including the benefits of a pre-diagnostic check, before you’ve even hooked up your tool.

Good Diagnostic Habits

Most technicians will agree that one key to their diagnostic success is getting into the habit of following a logical, step-by-step process each time they are trying to locate the cause of a customer’s concern.

It’s about more than simply following manufacturer guidance – it’s a process that allows you to gather as much information as they can quickly and efficiently.

And it takes advantage of all of your senses – including smell, touch and sight – and more importantly the ability to think critically and to analyse all of the information you’re taking in.

The process usually starts by focusing on the customer’s concern but a pre-diagnostic check can help you even further. Here’s how to go about one:

Before you even look at the vehicle, make sure you understand the customer’s concerns

  • As you approach the vehicle, try to get a feel for how it's being taken care of by noticing its appearance – both inside and out
  • Once you’re ready to get to work, perform a closer visual inspection with a focus on safety-related items such as the wiper blades, tires, brake pads and all the lights
  • Under the hood, inspect fluid levels and condition, along with the condition of belts and hoses
  • Look for anything that just isn’t the way it should be and make a note of your discoveries so you can share all of your recommendations at once
  • Then connect your Snap-on diagnostic tool to the vehicle and run a pre-scan report to identify any diagnostic trouble codes (DTCs) stored in the engine control units (ECUs)
The Importance of Vehicle System Scan Reports

Pre- and post-repair vehicle system scans have become a very useful step in a workshop’s diagnostic process.

Running a pre-scan before any vehicle work is done means any hidden issues can be located and the customer can be made aware of them from the outset.

The pre-scan code identification helps speed the diagnosis and repair, and when it is followed by a post-scan after work is finished, the report confirms that all concerns were dealt with properly.

Being able to give customers a copy of their reports also provides extra satisfaction as they can take away an easy-to-read statement of what was discovered and subsequently resolved.

Reports can also be printed or e-mailed to customers as well as used to fulfil mandates by manufacturers and many insurance companies for pre- and post-collision work.

Pre- and post-scan reports can be carried out on the Snap-on ZEUS™ and APOLLO-D8™ scan tool, along with the VERUS®, MODIS™, SOLUS™ and ETHOS® families of products.

APOLLO-D8, MODIS Edge™, MODIS Ultra™ and SOLUS Edge™ users can benefit from automatic synchronization of reports to the Snap-on cloud system on

From there, reports can be printed, e-mailed or sent via text message to customers and insurers, and can be accessed quickly in the shop.

Be More Efficient

So as you can see, by taking the time to fully gauge the condition of the vehicle you can make more efficient decisions when it comes to the repair of the customer’s original concerns and locating as-yet unidentified issues that the customer needs to be aware of.

With the ever-growing use of advanced safety systems and other electronics, your customers are increasingly dependent on you to keep their vehicles – and ultimately their families – safe.

Learn more about the full range of diagnostic tools and software from Snap-on.

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