Your Tool Experts for Diagnostic Tools
There is more computer processing capability in a modern car than the spacecraft that landed on the moon, so it is no surprise that today’s auto mechanics need sophisticated diagnostic tools to help them diagnose problems.
Auto diagnostic tools run range from quite simple devices easily used by DIY enthusiasts to complex high-end tools found in the hands of professional automotive technicians. Some diagnostic tools are readily affordable, whereas others are more of an investment, only you can judge this.
Basic Diagnostic Tools
Whilst some auto repairs should only be completed by fully trained mechanics, some basic tasks can be done by anyone using these basic diagnostic tools.
- Mechanic’s Stethoscope: Handy tool used to pinpoint worn bearings, engine faults and other mechanical noises.
- Circuit Tester: Designed for detecting low voltage circuit faults in autos, cars, bikes etc.
- Auto Timing Light: Used for checking ignition timing on automotive, agricultural and marine engines.
- Auto Vacuum gauge: For measuring engine air pressure.
- Vacuum Pump: A multi-functional tool used to test a variety of essential vehicle settings and operations.
- Fuel Pressure Gauge: A fuel pressure tester can quickly indicate if a fuel pump is defective or inconsistent in pressure flow.
Diagnostic tools are not just for the modern computer-based car engines, they are also required for older cars and these basic tools are helpful for the dedicated DIY auto enthusiast.
Advanced Diagnostic Tools : Scan Tools and Code Readers
Scan Tools and Code Readers
On-board diagnostics (OBD, or more specifically OBD2) have been available for over 20 years and are now an integral part of most cars. Code Readers and Scan Tools are the basic of the more advanced diagnostic tools, and are designed to scan and read engine codes to diagnose fault codes or status codes. It’s no different to any computer generated code and is quite straightforward to use and understand. The diagnostic tools simply read the code and look it up in order to make an assessment.
The process can be as easy as clearing the fault code, avoiding you having to take your car into the garage for a more expensive diagnosis. Using these tools are also useful for checking your auto repairs are fixed, without generating any other faults.
Depending on the diagnostic tool used, you may have the option to view additional information and to create your own list of parameter IDs (PIDs). Before spending a lot of money on a tool, take a moment to evaluate whether you need all of the features, perhaps saving you money.
Scopes & Other Meters
In addition to scan tools and code readers, scopes and other meters are useful diagnostic tools for auto mechanics. Perhaps the most essential tool in the category is an auto multimeter, which can be used to test a car’s electronic ignition system and to measure the dwell time of the ignition system and the engine speed.
Beyond basic scopes and meters for DIY use, professional automotive diagnostic tools tend to be quite expensive and perhaps neither cost effective or required in a home garage. Pro tools typically combine a scope, DVOM and troubleshooting techniques in one unit.
Foxwell NT301 Car Diagnostic Scan Tool
A popular example of an auto diagnostic tool is the Foxwell NT301 which will scan, read and clear engine fault codes. The NT301 displays scanned data in numeric or graphic formats, including data from the oxygen sensors if fitted.
The Foxwell NT301 is compatible with most petrol (from 2001) and diesel (from 2004) cars. The tool offers fault code definitions on-screen, reads & clears freeze frame data. It is easy and straightforward to use, making it ideal for DIY auto enthusiasts.
One of the key features of an auto scan tool is their ability to switch off check engine lights, saving a trip to the main dealer or local mechanic, some of which will charge almost as much as the cost of the scanner.
Fault codes are stored in the code reader, with updates readily available by connecting the scanner to the Internet using a usb cable. The NT301 also identifies VIN data, allowing for real-time data to be viewed and cleared.
The NT301 takes it’s power supply direct from the car, meaning batteries are not required.

Advantages of Using a Car Diagnostic Scan Tool
There are a number of advantages of using car diagnostic scan tools. Read our reviews of the best OBD-II Engine System Diagnostic Tools.
Bosch Oxygen Sensors
Pioneered by Robert Bosch in the 1960s, Bosch Oxygen Sensors have led the auto market ever since with their Premium and Wideband Sensors.