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Everything You Need To Know About 'Free' Diagnostics

Everything You Need To Know About 'Free' Diagnostics

We've all been there. You're late for work, hop into your car, and you hear that alarming 'ding!' When you look down, there it is, the worst thing imaginable – the dreaded 'check engine light.' You aren't sure what to do, so you drive to the closest place that advertises that they can diagnose check engine lights. They come out to your vehicle and pull out their code scan tool and plug it in. Five minutes later, they say, 'Hey, you have a P0440. Check your gas cap, and if it comes on again, come back.' You tighten your gas cap, cross your fingers, and go about your business only to have it pop back on 20 minutes later. Now, you're sure that it's an issue, and when you go back, they tell you, 'Well, it's the fuel tank, and that'll cost you $900.' But is it really?

Here's everything you need to know about 'free' diagnostics.

There are plenty of auto parts stores that offer 'free' check engine light scans. You can buy the scan tool right from

Dustin Mellor, District Manager for VIP Tires & Service

Amazon if that's up your alley. But, 'free' diagnostics aren't really a diagnostic. The scan tool can tell you where the issue is happening, but it can't tell you exactly what it is. That's why it's best to have an experienced certified automotive professional spend time to diagnose the real issue behind your code.

Our District Manager, Dustin Mellor, had a great way of putting it. He said, "It's a lot like going to your doctor and saying, 'hey, my foot hurts.' They take your temperature and say, 'well, you have a high fever, so that's probably why your foot hurts.' It's not really giving you an answer, so that's why we recommend a real diagnostic for our customers. If your doctor knows that your foot hurts, but he doesn't know why it's likely that he'll refer you to a specialist. So, it's kind of the same scenario. A code scan tool can tell you that there's a problem, but it can't tell you what it is. You have to be referred to a specialist, and that specialist is my technician. "

So, if the code tool tells me where the issue is, why is it so complicated?

There are going to be times when a scan tool is all you need! Did you know that if you keep your vehicle running while you pump gas, you can cause a code? Even having your gas cap a little loose can throw a code! But, the problem happens when the store or mechanic uses the scan tool and pulls a code and automatically tells you that it's this part or that part.

But, there are times when a code could be dozens of things, and sometimes parts stores will dilute it down to what it might commonly be. Dustin had a great example. "So, say you pull a code, and they say it's most likely your plugs. So, you could just replace your plugs, but you have a 50/50 chance that that's what the issue is. But some cars take 3 hours to put plugs in. So, now you've taken 3 hours to put plugs in and then find out it wasn't the issue after all." And all that labor adds up! Three hours of labor could cost you close to $400!

So, why do diagnostics take an hour of labor?

Code Scan Tool being held by an ASE certified professionalWhen technicians are diagnosing check engine light codes, they're going step-by-step through a flow chart of wiring diagrams, in-depth testing on electrical circuits, and using meters to test the amperage from the battery, and that takes time. Sometimes, those flow charts are 31 pages long. Some systems in newer vehicles can't work on less than ten amps, and if you've got a bad battery, then it will throw a lot of codes that you'll spend a ton of money and be forever chasing if you just throw parts at the problem instead of digging deep and finding the real issue.

Dustin experienced this recently at one of the stores in his district. "Recently, we had a vehicle in Rockland, ME that had disabled the entire fuel pump, starting system, and everything. My technician found it was actually ground wires. We set it up with a brush, got it down to the raw metal, and put the bolts back in, and it was fine. Someone could have gotten that and said 'it's got a fuel pump code, let me put a fuel pump in.' But, we took 2 hours to go through every step and found the common denominator and went there first. It might have taken 2 hours of diagnostics, but it would have been $900 to replace a fuel pump. We just want to get you the right answer."

Get the right answer and save yourself time and money!

So, in the end, anyone can pull a code for you when your check engine light comes on, but only a certified automotive professional can truly diagnose the real issue behind that warning light. Whether it's your local mechanic or the Certified Automotive Professionals at VIP, don't settle for just a code scan. Make sure you get the right answer with a diagnostic!

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