The Ultimate Buying Guide for Car Diagnostic Scanners

There are many different brands and models of car diagnostic tools with big price differences in the market. This can easily cause confusion, below is a list of the vital questions to ask the diagnostic salesman to make sure you are getting the functionality you need and secondly to make sure you don’t get overcharged, this way you can compare scanners effectively.

Scanner Coverage Questions

What ECU* systems can it access? Make sure you get the correct diagnostic software for cars
From 1996 in the USA and 2001 in Europe, all vehicles had to by-law abide by specific emission standards, this is known as OBD2 or EOBD software. This is able to test and monitor emissions-related components on the engine. Some entry-level scanners only can only access this system to read fault codes related to engine emissions only. The engine is only 1 of up to 70 different ECU’s (electronic controlled modules) that can be accessed by a scanner.

What manufactures does it cover?
The OBD2 software will cover all manufacturers as it is the law that all manufacturers have to implement that access to their systems. Diagnostic Scanners that are able to cover more than just the engine ECU system have software called “Manufacture Specific Software”, this is specific software for the different manufacturers, as the ECU system communication are different from manufacturer to manufacture. So make sure the Scanner covers the manufactures you plan to serve.

Does it come with OBD1 plugs for older vehicles?
Vehicles from the 1980’s up to 2001 have their own unique design depending on the manufacturer. This is called an OBD1 plug when OBD2 standards were introduced all plugs were standardized to 16-pin styles. So if you are planning on working with vehicles older than a 2001 year model, make sure the scanner you looking for, either has OBD1 plugs included or the option to purchase them as extras.

Scanner Functions & Benefits Questions

Can It Read Fault Codes & Provide Descriptions?
Some scanners will only give you the fault code and no description, this then creates extra work for you to go and find out what the fault code means.Make sure you the scanner gives you both!

(e.g. Code P0171 – System Too Lean Or Code 51 – Misfire Detection Cyl 5)

Also, make sure what systems the scanner can access. Sometimes scanners are limited to only certain control modules (e.g. only Engine, ABS, SRS & Transmission – no Instrument cluster, aircon and other body control, chassis, communication modules)

Can It Clear The Fault Code (Warning Lights)?
Some scanners can only read fault codes, make sure it can erase the fault codes as well. Erasing certain fault codes after a problem is fixed will remove the warning lights on systems such as engine, ABS and airbag.

Does it have service functions?
Oil Reset, EPB, BMS, SAS, DPF etc…

Can It Provide A Diagnostic Report Print-Out / Digital Report?
An important benefit that most workshops need is to be able to provide their client or the insurance provider with proof-of-work. It is often best to provide a before and after diagnostic report to your client to prove that the work has been done and to eliminate any uncertainty.

Can It Access Live Data Values?
The Live Data function shows real-time values of the vehicles PID data such as engine temperature, engine speed, throttle position, oxygen sensor rich/lean indication, mass air flow etc…

Will the Scanner allow you save or print this data is another important question? As sending this to clients or saving it to compare with similar vehicles can be useful.

Can It Do Live Actuation Testing?
Some ECU’s permit you to actuate (switch On/Off etc. etc.) some of their operating circuits in order to diagnose the functionality of the relevant actuators. i.e relays, fans, door locks, lights, injectors, A/C clutch etc. etc.

Can It Do ECU Coding / Bi-Directional communication ?
Some vehicle spare parts come with ‘coded’ numbers that have to enter into the ECU in order for it to recognize and/or accept the new (or second hand) part. ECU’s, Injectors, spare keys, radios and even starters are now coming out ‘coded’. This function is indispensable if you need to change those vehicle parts.

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