Code Reader or Full System Scanner: Which Scanner is the Best Fit for Your Repair Job?
A code reader and a full-system scan tool are not the same thing. A code reader is only able to pull basic fault codes, while a full-system scanner is able to scan codes, read live data, and run active tests that allow users to perform deeper diagnostics. If your check engine light is on and you don’t know why, a code reader will do the trick. If your ABS or airbag light is on in the dash, you’ll need a full-system scanner to see what’s going on.
At a Glance
- Code reader: Can only read engine codes, and are usually available to borrow from auto parts stores, like Advance Auto Parts.
- Full system scanner: Can access every module, read live data, and issue commands that make components operate. These are not commonly available to rent or borrow.
You can rent a YOUCANIC scanner here, or email YOUCANIC’s support team with your VIN. Our team can confirm compatibility before you place your order!
What a code reader does
A basic OBD-II code reader plugs into the port under the dashboard and talks to the engine control module (ECM). It will give you stored emissions-related codes, usually clear them, and on better units show some live engine data.
🔧 Find out what is actually wrong before you pay someone to guess
Dealer level diagnostics at home with the YOUCANIC UCAN-II Pro.
- ✔ Covers most makes and models, including many luxury brands. Send us your VIN and we will confirm your car before you order
- ✔ Reads every module, not just the engine, so you find the faults a basic reader says are not there
- ✔ Commands the car: test a fan or pump, bleed ABS, retract an electronic parking brake, register a battery
- ✔ No subscriptions. Free lifetime updates, so the price you pay is the whole price
- ✔ Backed by real mechanics in the USA you can email before and after you buy
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If your check engine light is on and you don’t know why? This is the tool for you! Better yet, most chain auto parts stores in the US will loan you one for free, which can come in handy if you don’t already have one in your glovebox.
Where it stops
While basic code readers can be a nice-to-have, a car has many computers, which means there are many different components that can throw fault codes. If the ABS or airbag warning lights have come on in the dash, a scanner that can only communicate with the car’s ECU isn’t going to cut it.
A full-system scanner is able to read and clear codes in every module on the car, and more. On top of reading more codes, full-system scanners can run bidirectional tests and show live data parameters, which allows for deeper diagnostics.
Which one should you rent?
You don’t need to rent anything if the only issue you’re experiencing is that pesky check engine light. Borrow one from an auto parts store for free! S
Got another light on in your dash? Rent a full system scanner. These scanners are also great if you need to perform a service function to finish a repair. Renting with YOUCANIC means you get a scanner for $85 per week to read fault codes, run active tests, and perform teach-in procedures like battery registration.
Want to make sure it is compatible before you rent one? Email YOUCANIC support with your VIN, and we can confirm coverage for you.
Frequently asked questions
Why did my scan show no codes when a light is on?
Almost always because a code reader was used on a fault stored outside the engine module. Parking brake, ABS, and airbag codes need a full-system scanner.
Can I rent a code reader?
You can usually borrow one for free from a large parts store. Renting one rarely makes sense.
Is a full system scanner harder to use?
Not at all! It presents a list of modules and a list of functions. The difficulty is knowing which function your car needs, which is why we ask for the VIN.
Rent a YOUCANIC full system scanner: $85 for seven days, with shipping covered both ways!
