An electronics checklist for buying a used car

Before the scan

For the electronic check, you plug the 2dakika OBD-X1 into the car's OBD port and start the scan in the app. The port is usually under the steering wheel. Scan the car with the seller's permission.

Keep the ignition on and the engine off throughout the scan; some modules don't respond while the engine is running. If you scan after a test drive, just turn the engine off and turn the ignition on. On most cars a scan takes under 2 minutes, and the VIN is read from the car.

The checklist: 6 things to look at in the report

When the report is ready, go through these in order:

• Current faults: Codes are listed with plain-language descriptions and a severity (Priority, Warning, Info). If the engine computer stored them, you also see the engine temperature, rpm and speed at the moment the fault occurred. Severity is a guide; if a warning light is flashing or there are symptoms while driving, have the car checked at a workshop.
• Fault history: Codes that occurred earlier and are stored in a module's memory but aren't active now sit in a separate list, with their severity shown too. This is where you can work out which repairs to ask the seller about.
• Distance since the last clear: On cars that report it, the report shows how far the car has been driven since the fault memory was last cleared. How to read it is explained below.
• Mileage label: The odometer is compared with the records kept by modules such as the engine, transmission and ABS. The result comes as a label such as "Mileage consistent", "Mileage mismatch — get it checked" or "Mileage inconsistent — possible rollback"; it is a pre-check, not a definitive finding.
• Modules and part compatibility: Part number and software version for each module, plus build and programming dates if the module reports them. Modules whose stored VIN belongs to another car are flagged as "From another vehicle: make, model, year". This is not a problem in itself, but it deserves attention on modules that keep mileage, especially the instrument cluster. A module made years after the car may also have been fitted later.
• Vehicle status: 12 V battery health on cars that report it, battery voltage on others; battery health on supported electric and hybrid models. On diesels whose engine computer reports them, DPF ash and soot levels and regeneration history come with a plain summary (for example "Looks normal" or "Check recommended").

Were the fault codes cleared before the sale?

Clearing doesn't fix the fault: if the problem persists, the code and the warning light come back. Clearing codes after a repair is a normal step; what matters is when and why it was done. If codes were cleared recently, the current faults list may look empty for a while, so also look at these lines in the report:

• Distance since the last clear: A short distance can point to a recent clear. This counter can also be reset by disconnecting the battery or by workshop work; on its own it doesn't show bad intent.
• Cleared with 2dakika: Every clear made with 2dakika is recorded for the car. If the VIN was read from the car in both scans, the clear shows up on this line in the car's later reports, with its date and module count. A clear in the last 30 days appears as a warning in the report summary.
• Emissions readiness monitors: Clearing resets these too; some normal driving is needed for them to complete. If the car reports them, the report shows how many have completed.

What does it mean when a section can't be read?

Which modules and data can be read varies by car. Some modules, for example those behind a security gateway, can't be reached; that doesn't mean the car is faulty. A section missing from the report isn't a negative finding on its own either.

The report also lists separately which modules' fault memory was read and which couldn't be. Codes stored in modules that couldn't be read may be missing from the list, so "no fault codes" and "couldn't be read" aren't the same thing. The mileage comparison is also limited for many makes: "Not cross-checked" is not a negative finding about the car, and it doesn't mean the mileage was checked either.

What the electronic check doesn't show

The 2dakika report is not a definitive finding and not a professional inspection report. It does not cover the car's mechanical condition, accident/paint history, TRAMER or service records. So use the electronic check before or alongside a professional inspection; a report taken before the inspection can help you pin down what you want the inspection to look at closely.

Before you decide to buy, also look at:

• TRAMER record: damage records reported to insurers; having no record doesn't mean the car has never been damaged.
• Professional inspection: an in-person examination of the bodywork, paint and mechanical condition.
• Official mileage records, and service and maintenance documents.
• The registration document and the paperwork for the sale.
• Test drive: brakes, steering, gear changes and any warning lights that come on while driving.

Share the report, open the original

You can save the report as a PDF or share it with a link and QR code, so you look at the same data with the seller or at the inspection. You can revoke sharing anytime. The VIN is masked in the report (first 3 and last 4 characters), and shared reports aren't indexed by search engines.

If a seller has sent you a report, scan the QR code on the PDF: it opens the original report on 2dakika, and readings are signed by the device. Values are fixed at scan time; to see the car's records as they are today, a new scan can be done before you buy.