How to Rent an OBD2 Scanner and Check Loan Options
The Short Answer
You usually can't rent an OBD2 scanner for a daily fee. Instead, you borrow one through an auto parts store's tool loan program. AutoZone's version is called Loan-A-Tool. You pay a refundable deposit, take the scanner home, and get your deposit back when you return the tool in good condition within the store's return window. Some other parts chains run similar loaner programs.
An OBD2 scanner, also called a code reader or scan tool, plugs into your vehicle's on-board diagnostics port. It reads the diagnostic trouble codes (DTCs) stored when the check engine light comes on. In the United States, OBD-II has been required on cars and light trucks since the 1996 model year. Older vehicles, and vehicles from other markets or years, may use different systems that a standard OBD2 scanner can't read.
Several details vary by store and change over time, so check them with your local store before you go:
Whether a scanner is in stock to borrow. Which scanner model is offered. The deposit amount. The return deadline. Whether a free in-store code scan is available at that location.
How Tool Loan Programs Work
Most parts-store loaner programs work much the same way, even though the exact terms differ:
You pay a deposit, often roughly the price of the tool, by card or cash. The store lends you the tool, sometimes with a receipt or agreement listing the return terms. You return the tool, with all its cables and its case, to a participating store before the deadline. The store checks that the tool is complete and working, then refunds the deposit. If you keep the tool past the deadline or return it damaged or incomplete, you may lose some or all of the deposit.
Not every location carries a borrowable scanner, and stock can run out. Call ahead or check the store's tool loan listing to confirm before making the trip. Also ask whether you can return the tool to a different branch of the same chain.
Borrowing, Buying or Getting a Free Scan
Which option fits best depends on how often you need codes read and how much detail you need. This guide doesn't include current prices or tool specifications, so treat these comparisons as general trade-offs rather than cost figures.
Option | Upfront cost | Best for | Main limitation; Borrow through a loan program | Refundable deposit | A one-off diagnosis or reading codes at home over a few days | Depends on stock and the return deadline; the tool may be a basic model; Free in-store code scan | Usually none where offered | Quickly finding out why the check engine light is on | Not offered at every location; you get the codes but not ongoing access to a tool; Buy a basic code reader | Purchase price | Repeated use, several vehicles, or checking whether a repair worked | You pay upfront and the features vary widely; Professional diagnosis | Shop diagnostic fee | Complex faults, intermittent problems, or systems a basic reader can't access | Highest cost, but includes expert interpretation
Here is how to choose:
If you only need the codes once, a free scan or a borrowed tool usually makes sense. If you want to clear a code, drive the car, and then check whether the fault returns, a borrowed scanner gives you that time. Buying one makes sense if you'll do this often. If the problem involves ABS, airbags, the transmission or another system beyond basic engine and emissions codes, a basic reader may not be able to read it. In that case, a more capable scan tool or a repair shop is the better route.
How to Use a Borrowed OBD2 Scanner
What you'll need: the scanner and its cable, your vehicle, and a way to write down or photograph the codes. Your owner's manual helps you find the diagnostic port, and the scanner's instructions explain its menus.
1) Park on level ground, set the parking brake, and turn the engine off. Don't use the scanner while driving, and keep the cable away from the pedals and steering. 2) Find the 16-pin diagnostic port. On most vehicles it's under the dashboard on the driver's side. If you can't see it, check the owner's manual. 3) With the ignition off, plug in the scanner firmly. 4) Turn the ignition to the on position without starting the engine, unless the scanner's instructions say otherwise. The scanner should power up from the port. 5) Follow the scanner's prompts to read stored codes. Record every code exactly, including any pending codes, before you do anything else. 6) Look up what each code means, either in the scanner's built-in library or a trusted repair reference for your exact make, model, year and engine. 7) Turn the ignition off before you unplug the scanner.
To confirm you're done, check that you've recorded all the codes, unplugged the scanner, and packed it with all its parts for return.
Clearing codes: most scanners can erase codes and turn off the check engine light. This does not fix the underlying fault. Clearing codes also resets the vehicle's readiness monitors, which are self-tests the car runs during normal driving. Until those self-tests finish, the vehicle may fail an emissions inspection. Only clear codes after a repair, or when you deliberately want to see whether a fault comes back.
When to stop and get professional help:
A flashing check engine light usually means a severe engine misfire that can damage the catalytic converter. Reduce driving and have the vehicle inspected promptly. A warning light for brakes, airbags or steering points to safety-critical systems. These need qualified diagnosis and repair. If the scanner won't connect, the port may have no power, often because of a blown fuse. The vehicle may also not support standard OBD2. Check the owner's manual or ask a technician rather than forcing the connector.
What This Guide Can't Confirm
Some details weren't available when this guide was written:
Current deposit amounts. Return deadlines. The specific scanner models offered. Whether free in-store scanning is available in your area.
These vary by retailer, location and jurisdiction, so confirm them directly with the store. Vehicle compatibility also depends on model year and market, so check that your vehicle supports OBD2 before you borrow a tool.