When you’re in the market for a used car, ensuring you’re making a sound investment is paramount. A reader recently wrote in to Car Doctor seeking advice on whether bringing a computer scan tool is a wise move when inspecting a potential purchase. The question was: “What do you think about bringing along a computer scan tool to test the car before buying it? Do you think the dealer or private seller would mind?” Here’s a comprehensive look at why a Used Car Scanner can be your best friend in the pre-purchase inspection process.
The Power of a Used Car Scanner: Unveiling Hidden Issues
Bringing a used car scanner, also known as an OBD2 scanner or car diagnostic tool, is not just a good idea – it’s a smart move for any discerning used car buyer. As a seasoned mechanic, I believe that using a scan tool is beneficial for both the buyer and the seller, fostering transparency and informed decisions.
Detecting Fault Codes: Beyond the Dashboard Warning Lights
The primary function of a used car scanner is to read diagnostic trouble codes (DTCs), often referred to as fault codes. These codes are generated by the car’s computer system when it detects an issue with various components, from the engine and transmission to the braking and emissions systems. While some problems illuminate the check engine light or other dashboard warning lights, many underlying issues may not be immediately apparent. A used car scanner delves deeper, accessing the vehicle’s computer to reveal both active and stored fault codes that might not trigger a visible warning.
Spotting Cleared Codes: Identifying Potential Cover-Ups
One of the most valuable insights a used car scanner provides is the ability to detect if and when the fault codes were last cleared. Unscrupulous sellers might disconnect the car battery to temporarily reset the computer and extinguish warning lights, masking underlying problems. If a scan reveals that codes have been recently cleared, it should raise a red flag. This could indicate that the seller is aware of existing issues and attempting to conceal them, hoping the problems won’t resurface during a quick test drive. This knowledge empowers you to ask pointed questions and potentially avoid purchasing a vehicle with unresolved mechanical issues.
Verifying Mileage and More: Advanced Scan Tool Capabilities
Depending on the sophistication of the used car scanner, you can access even more valuable data. Some advanced scan tools can read data from various modules within the car’s computer network, potentially revealing discrepancies between the odometer reading and the actual mileage recorded by the engine control unit (ECU) or other modules. While not all scanners offer this feature, it’s worth considering a model that does for added peace of mind. Beyond mileage verification, advanced tools can also provide live data readings from sensors, offering a snapshot of the engine’s real-time performance.
Will Sellers Mind a Used Car Scanner Inspection?
You might wonder if a used car dealer or private seller would object to you using a scan tool. In most cases, a legitimate and honest seller should not have any issue with it – and might even welcome it. Using a scanner demonstrates your thoroughness as a buyer and can expedite the process by quickly identifying any pre-existing conditions.
For sellers, knowing that a potential buyer is using a scan tool can also be advantageous. It can highlight that they are dealing with an informed buyer who is serious about the purchase. Furthermore, if the scan comes back clean, it reinforces the vehicle’s condition and can build trust, leading to a smoother transaction.
However, if a seller strongly objects to you using a used car scanner, it could be a warning sign. It might suggest they are trying to hide something and are uncomfortable with a deeper inspection of the vehicle’s electronic systems. In such instances, it’s prudent to proceed with caution and perhaps reconsider purchasing that particular car.
Conclusion: Empowering Your Used Car Purchase
In conclusion, bringing a used car scanner when shopping for a pre-owned vehicle is highly recommended. It’s a small investment in a tool that can provide significant insights into the car’s health, potentially saving you from costly repairs down the road. By detecting fault codes, identifying cleared codes, and even verifying mileage, a used car scanner empowers you to make an informed decision, ensuring you drive away with a reliable used car and peace of mind. Don’t hesitate to use this valuable tool – it’s about making a smart and confident purchase in the used car market.
