Skip to content
SuperMoney logo
SuperMoney logo

How Much Should You Pay for a Car Diagnostic Test?

Last updated 03/14/2024 by

Jessica Walrack
Your check engine light comes on — you’ll need a car diagnostic test. What does it mean, how much should it cost, and where can you get one? Let’s start with a little background.

Get Competing Personal Loan Offers In Minutes

Compare rates from multiple vetted lenders. Discover your lowest eligible rate.
Get Personalized Rates
It's quick, free and won’t hurt your credit score

What does the check engine light in your vehicle mean?

The majority of modern fuel-injected vehicles have automatic transmissions, fuel injection systems, and ignition systems controlled by the main computer in your vehicle. These computers continuously receive data from dozens of sensors to optimize the combustion process. Almost every aspect of your vehicle is monitored via sensors (such as the exhaust system, gas cap, oil tank, ignition coils, and engine) that detect problems with your vehicle.
When something goes wrong with one of these vehicle systems, these sensors report a problem to the main computer (otherwise known as a motherboard) in your vehicle. A.K.A., your check engine light will turn on. Now, what do you do? Your vehicle is telling you there’s something wrong with it, but how can you get the information to resolve it? Well, it’s time to look into car diagnostic tests.

What is a car diagnostic test?

Car diagnostic tests provide a fast way to check for issues with a computer. These diagnostic services give you trouble codes you can use to estimate the cost of auto repair.
“A good car diagnostic test will inform you how long the issue has been present, both in real-time, key/start cycles, and drive cycles, while also telling you how many times this error has occurred during that time,” says Matt Barton of The Hero Labs. “This tells you if the problem was a fluke or if you have a degrading system that will need to be addressed.”
This means that a car diagnostic test does a system analysis that reads the error codes from your check engine light in layman’s terms. With that said, many errors will not trigger a check engine light. With this in mind, it’s not a bad idea to get a car diagnostics checkup periodically. The cost of this test is usually cheaper than a full-blown vehicle inspection, anyway. A diagnostic test can even be free if you know where to look.

How much should a car diagnostic cost?

“Typically, it should only cost one hour of shop rate time (the amount a given shop charges for their hourly rate),” says Barton. Depending on your region, this figure should sit between $65 and $100.
RepairPal reports that a car diagnostic test costs between $88 and $111 before taxes, and Popular Mechanic says it can cost from $20 to $400. Both of which can be more than the average cost of a car diagnostics test but less than a time-consuming vehicle inspection. However, the cost is worth it know the problems your vehicle could have.
As with any financial decision, it’s smart to check at least three places before you commit. This can be done through checking reviews, email, or calling the store (or several stores) yourself. Since several auto repair shops will offer free car diagnostic tests, it is worth asking what the car diagnostic cost first.

Can you get a free car diagnostic test?

Barton says, “As a mechanic and small business owner, my job is to make money, so I always include a free check with service. Many places will do this if you just ask, and hey, a free check never hurt.”
On the other hand, some shop owners will try to use your car diagnostic test to convince you that your car trouble is catastrophic to inflate the repair cost and push you to spend more. Be sure to check reviews and work only with the more reputable establishments. If you have qualms about a diagnosis, get a second opinion because the more information you have, the less you can be manipulated. It may cost more initially for more diagnostic tests, but it will be worth it to your wallet!
Unfortunately, not every car diagnostic test is a scam. Sometimes you just need to bite the bullet and pay for an expensive repair or part replacement to keep your car alive. After all, a vehicle purchase is a lifetime investment, and the value of having your own motor vehicle can’t be matched.

What do you do if the repair cost is just too much?

Thankfully, there are various tools available at many locations, both in-person and online, to finance your car diagnostic test. For example, these tools can include services, products, and special offers by businesses. After you’ve compared store reviews, asked all the appropriate questions of your chosen mechanic and technician, and identified the underlying issue behind your car’s diagnostic test, it’s time to talk financing.
You need a car diagnostic test, possibly your engine needs to be repaired, and pricing shouldn’t be your #1 problem. Some services, products, and offers can assist in paying for costly repairs. You need a technician you can trust, the information about the car problems behind the error code in your car, and a fast repair at a reasonable price. However, even if you are facing a large bill, you have options.

4 ways to pay for expensive repairs

That bill just from a car diagnostic test can be daunting depending on where you go – not even mentioning the overall repair. Thankfully, there are a variety of ways to pay it off! If you end up needing an expensive repair or any diagnostic trouble and don’t have the funds to pay for it out-of-pocket, here’s a quick list of financing options to consider.

Get an unsecured personal loan

Getting an unsecured personal loan is one of the easiest ways to borrow cash fast. Select your lender, gather some data on them, apply online, and, upon approval, you’ll have the money in your bank account in as little as a day. All you need is a computer to get started from any location. Look for low-interest rates, minimal fees, and good customer service.

SuperMoney may receive compensation from some or all of the companies featured, and the order of results are influenced by advertising bids, with exception for mortgage and home lending related products. Learn more

Loading results ...

If you need help finding your best offer, you can use our personal loan engine to get personalized offers from dozens of lenders competing for your business. Some sites allow you to subscribe via email as well!
Since different personal loans come with different rates, fees, and requirements, be sure to check out what the best personal loans are to ensure that you choose the best option for you. You can do this by gathering data on your chosen lender from reviews, sending an email, or calling.

Credit card with a no-interest offer

Lastly, consider getting a credit card with a no-interest introductory period to get a car diagnostic test and resolve whatever issue your vehicles are having. During the promotional period, you will pay no interest on your balance. If you use it to pay for car repairs, you will have time to pay it off before the interest kicks in. However, try to only pay what you need to for the repair because it can be easy to overextend your credit card funds.

SuperMoney may receive compensation from some or all of the companies featured, and the order of results are influenced by advertising bids, with exception for mortgage and home lending related products. Learn more

Loading results ...

The catch? When the promotional period ends, the interest rate skyrockets. Only use this option if you’re confident you’ll pay off your credit before the promotional window closes, so only spend what you need to fix issues or errors in your car. In addition, you’ll have to get approved based on your credit score. So this option isn’t well-suited for those with a poor-to-fair credit score.
Read about more quick ways to borrow money here.

Borrow from friends or family

Noone particularly likes to borrow money from friends and family, but what if all of the locations you go to elsewhere won’t lend you the money you need to fix that trouble code in your car? The only recourse is to consider asking a friend or family member if you can borrow the money. It can be your only quick fix to your diagnostic trouble, no matter what the tests say or what store you go to.
By doing this, you can usually pay less than you would pay to an official lender, and you won’t need to pass a credit check. There’s usually no or minimal interest, and you can work out a payment plan that will help you keep your house (and car) in order in the long-term. The downside? If something goes wrong, your personal relationship is at risk. Be sure to have a solid repayment plan in place to avoid emotional strain.

Get your car back on the road

Even though a check engine light can bring bad news and a potentially costly car diagnostic test, the sooner you find out about a problem, the better. Otherwise, one problem can turn into many more. Those pesky trouble codes can get out of hand quickly and should be handled quickly.
The scan itself should be around $100 but can range from $20 to $400. Depending on the problem and the mechanic you hire, solving the problem can cost even more. It’s best to keep the total cost in mind when it comes to approaching car issues.


Your primary goal is to get your car back on the road, up and running, and not to have to worry about getting to and from where you need to go. That check engine light can be a red flag that means there’s an error code somewhere, meaning potentially expensive parts and services to repair it. It could be your engine, oil tank, computers, etc., and one diagnostic test can find the error and resolve all of your problems.
You know what you have to do: go to a mechanic and get a car diagnostic test. But you might not necessarily have the means to pay for it right now. There are various ways to cover the test, so how do you pick the best one for you? SuperMoney can help with reviews for different services and special offers! Just register on the site with your email address and password and start scanning offers to find the best deal for you.
Need more information on how to finance your auto repair? SuperMoney can help. Or check out your options for an affordable personal loan here. Either way, always remember to check the reviews no matter the service, location, or price to find the best option for you. And remember, always do a road test after every repair!
Buying a new car? Learn how much should you spend by the 20/4/10 rule

SuperMoney may receive compensation from some or all of the companies featured, and the order of results are influenced by advertising bids, with exception for mortgage and home lending related products. Learn more

Loading results ...

Jessica Walrack

Jessica Walrack is a personal finance writer at SuperMoney, The Simple Dollar,, Commonbond, Bankrate, NextAdvisor, Guardian, and many others. She specializes in taking personal finance topics like loans, credit cards, and budgeting, and making them accessible and fun.

Share this post:

You might also like