Why Scan Tools and Diagnostics Drive Up the Cost of Your Repair Bill

May 15, 2012

One of the biggest complaints from auto repair consumers is the cost of repairs and why they are charged for diagnostics. These days, most shops will charge for diagnosing what is wrong with your car. Sometimes it is credited to the repair if the car is repaired in the shop and sometimes it’s an additional charge on top of the repair.

The question on most people’s mind is, “Why do I have to pay someone to tell me what is wrong with my car when I already know what it is?” Well, in most cases, the customer actually doesn’t know what is wrong with the car. They know that the Check Engine Light is on, or the brakes are squeaking, or coolant is leaking. But these are symptoms, not a diagnosis, and it can take time to determine what exactly is causing the symptom. Sometimes the problem can be found very quickly; other times, it can literally take days to determine exactly what is causing the problem, especially if it’s intermittent.

When diagnostics are performed, not only is the technician involved, but there are often specialized tools that must be used. Scan tools communicate with the onboard computers and a programing interface is used to update their programming. Oscilloscopes and multimeters are used to test electrical circuits and sensors. Listening devices can help isolate the cause of a mysterious noise. The list goes on and on.

Repair shops must purchase these special tools and they can be expensive. To recoup the cost, shops must charge for their use and how much time is involved not only in using the tool, but making sure their technicians know how to use it correctly. This is very similar to paying for an x-ray, where part of the cost goes to paying for the x-ray machine and part goes to paying for the x-ray technician’s time and education.

As our vehicles have become more complex, the tools needed for diagnosing them have become more complex and expensive, and so has the training on how to use them. While it may look simple to plug in a scan tool and read the fault code, that is really only the beginning of the process. Fault codes must be diagnosed to determine the actual cause of the problem.

Not all scan tools work efficiently on all vehicles and just like any other product, some scan tools are of higher quality than others. It’s pretty common for a shop to have multiple scan tools, five or more in many cases. Each scan tool can cost thousands of dollars, and software updates for each new model year drives the cost even higher. At the end of the day, shops can end up spending a minimum of $30,000 or more just on scan tools.

So, while your local auto parts store may use a $150 code reader to read your fault codes and reset the Check Engine Light, they are not diagnosing anything. In most cases, they are only trying to sell parts that may be related to a specific fault code and offer no guarantee that replacing the part will fix the problem.

Often with our newer vehicles, certain problems can be corrected by updating the software in one or more of the onboard computers. Previously, this type of work was done only by the dealer. However, in recent years, the government ordered the manufacturers to make this information available to independent repair shops as well.

And, as with everything else in life, this comes with a cost. Shops must purchase additional hardware specifically for programming. Also, each vehicle software update must be purchased from the manufacturer, either as part of a subscription or on a case by case basis. A colleague of mine recently visited an independent repair shop that was using factory scan tools and programming equipment for each of the models they worked on and they had already invested over $150,000.

Because our vehicles have so many computerized systems and the tools themselves cost so much, the price of diagnosing most vehicle problems has risen rather dramatically over the last few years. Shops can no longer avoid charging for their diagnostic time—there is simply too much cost involved in the training and special tools now necessary to perform a proper diagnosis.

In this case, I cannot help but see similarities between auto repair and medicine. There is no question medical training is much more extensive, and the diagnostic equipment is much more expensive, but the need to charge for a diagnosis is much the same. If you were to go to the hospital with a broken arm, which you had diagnosed yourself, they would not simply put your arm in a cast and send you home. They would “diagnose” your broken arm, most likely with an x-ray, which you would be charged for on top of what you pay for the setting and casting of your broken arm. And if the x-ray came back negative, and your arm wasn’t actually broken, you would still pay for the x-ray, just like you should have to pay for diagnostics on your car, even if they don’t end up pinpointing the problem with the first round of diagnoses.

Please try to keep this in mind the next time you take your vehicle in for repairs. Proper diagnosis is always necessary to determine what is causing the problem with your vehicle. Well trained technicians using the proper tools and equipment can usually get to the cause of most problems pretty quickly and they certainly deserve to be compensated for their time while doing so. That’s why it’s so important to go to a quality shop that has the tools and the people who know how to use them.

Want to find a quality shop near you? Check out a RepairPal Certified Shop.

About the Author

Jim Taddei has been in the automotive field since 1975 and has over 25 years of experience with General Motors products, achieving the designation of GM Master Technician. He is also currently certified as an ASE Master Technician, and holds an Advanced California Smog Check License. He has been the lead technician and team leader at a multi-line dealership. After leaving the dealership he spent a couple of years working in an independent shop and now uses his experience and expertise to help verify the quality of RepairPal Certified shops.

19 User Comments

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By , May 15, 2012
Absolutely awesome article! I am a technician for over 30 years and am amazed at the fact the consumers just dont get it. I have almost $100k in tools and equipment to diagnose todays vehicles and I need to be allowed to recoup my investment! I hope this article will help educate people!
By , May 15, 2012
This article is great! I am the bookkeeper, secretary/receptionist for a larger auto repair shop and this is perfect! I am going to print it and put it on the bulletin board for our customers to read. I have to repeat these same things to customers throughout the day, but this says it so much better than I do! Thanks
By , May 16, 2012
This is excellent information for the consumer, who mostly have the misconception plugging in a scan tool will reveal the problem with the vehicle. Any technician will tell you that is false. Educating consumers with this type of information is much needed!!!
By , May 16, 2012
Bravo author. I'm a mobile technician that provides the services you describe to area repair facilities that can't afford the tooling and training expenses. This allows their customers vehicles to be diagnosed and repaired correctly and keeps the vehicles in house. I offer these shops an alternative to having to send their customers to a dealer or the competition. Your article explains perfectly the need for my services and the justification of my fees. Thank you again for a well written,informative article to help explain to the vehicle owner and shop owner the importance of the proper tools and training. I have well over 100k invested and that doesn't even include countless hours in classrooms across the country just keeping up. Thanks again.
By , January 31, 2013
Great if it helps but as the consumer it told two techs two different things at different times same day. explain that one please!
By , March 27, 2014
What should a computer repair shop charge to diagnose your computer problem? What is fair to both the business and the customer? What exactly is a “diagnostic” anyway? I get this question a lot and it’s sometimes hard to answer. I always try to give the best value I can, but sometimes people just don’t understand what’s involved. A diagnostic simply means to find out what’s wrong with the computer. Usually, a technician can figure this out quickly, however, there are times when it can take hours to figure out what’s wrong. I’ll outline some common situations and how we handle them. Types of Diagnostic Scenarios: The technician knows immediately what’s wrong and soon as the PC is turned on. He knows what the general problem is, but needs to analyze further to find the exact problem. The PC is showing problems in several areas, or is giving very general error messages. It may have issues that can be caused by several different causes, so several tests need to be run. After repairing an obvious problem, other issues appear. As you can see, there can be a very broad range of situations. Some may require several test and analyses to be run. Often times, the diagnostic procedure is the same as the repair procedure, so as the technician tries different things, he actually repairs the problem. How we handle these situations? For Scenario 1, if the problem is obvious, there is no diagnostic fee. We just charge for the repair. For Scenarios 2-5, there is a $45 fee for desktops, or $65 for laptops. For laptops, things can get tricky. If it must be taken apart to diagnose, there is an additional $40 fee to put it back together (because this can take up to an hour). If the customer decides not to fix the laptop, they usually don’t care about putting it back together anyway, so there’s usually no extra charge. The Good News! Our diagnostic fees are always credited toward the repair, so if you repair the computer, there is actually NO diagnostic fee. It’s FREE! We only use diagnostic fees to cover our time if the customer chooses not to repair the PC. Sure, we sometimes lose money that way, but we feel it’s good customer service and generates trust. If you’re having computer problems, and want to find out more about us, please visit our Tucson Computer & Laptop Repair website. Better yet, give us a call and talk to us personally, at (520) 250-5948.
By , March 27, 2014
Charging for a diagnostic is like a gas station/convinience store charging .25cents for a book of matches a customer that buys a pack of smokes. If someone walks off the street without making a purchase and wants a book of matches then charge them. The matches cost money sure, so does the toilet paper in the bathroom, or the paper towels at the pump, but these are things you provide to the customer for free, as a courtesy, if youre not a greedy evil douche bag that is. Car mechanics are greedy, evil, douchebags that overcharge for everything and generally lie thru their teeth. Nobody every trusts them! Why is that?!?
By , April 18, 2014
C3ECUL I think this is a real great article.Much thanks again. Will read on...
By , May 11, 2014
v0B8ta Really appreciate you sharing this article. Much obliged.
By , June 01, 2014
These tools should cost $30. The electronics in them not complicated. They are so expensive because car system Manufacturers charge to license the software for their brake, fuel injection, air bag, etc. The fact is most of the technology is developed under grants from the department of the interior so we already paid for the work that created the technology. This is a classic example of charging the consumer because they can.
By , June 04, 2014
cGRhpo Thanks so much for the blog post.
By , June 18, 2014
iff0GP I value the article post.Thanks Again. Awesome.
By , July 04, 2014
u0RN0R Thanks a lot for the blog.Really looking forward to read more.
By , December 17, 2014
gMWKTx I think this is a real great blog post.Really thank you! Much obliged.
By , February 23, 2015
I agree with your comments but having experienced a disaster with existing test equipment, I have a question. If a problem proves elusive to conventional testing, why not develop a device that replicates the computer? Just unplug the computer; insert the appropriate connector; input the vehicle VIN and the device replicates the computer. The current methodology utilizes the process of elimination to finally discern that the problem is the computer itself, not a sensor. While expensive, it could minimize the technicians time in diagnostics and reduce the cost for the consumer. JR
By , June 04, 2015
"You completed a few nice points there. I did a search on the topic and found nearly all folks will consent with your blog."
By , September 10, 2015
Amazing! How much should I charge for using my soldering iron/spanner/brain then? Isn't it the entire reason one takes a car or anything along to an 'expert'(hopefully) to have the job done?
By , September 10, 2015
I paid for the work to be done on my car but still got charged for the diagnostic scan which I saw performed, $75! It took seconds. Wonder what my screwdriver is worth when I do a repair? Isn't this all a bit arse about face? After all it is just another tool for the job without which it may take much longer to do the job. A bit like all of us being rich and leisurely and doing 2 hours work a week like they said computers would do for us back in the 60's. Hope fades away...
By , March 10, 2016
Maybe we should charge by the hour like plumbers and electricians, that will fix the issue,Almost retired master, L1