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Running a car in the 21st century can be expensive, especially if it is out of warranty. Diagnosing faults can be particularly costly, especially if the repair facility is experienced in upselling to ensure you carry out your repairs with them.
The continuing computerisation of automobile systems means that repairs are often like-for-like component swaps (much the same as when repairing a desktop computer), which means the modern mechanic needs good understanding of electrical systems as well as those traditional mechanical components that are still in use.
What all of this means, however, is that you can save money on repairs on expired warranty vehicles be performing your own fault diagnosis using a special USB cable and a diagnostic utility. You can then use this information to trace a fault to a particular component (perhaps a temperature sensor, perhaps the brakes) and arrange the necessary repairs.
Automobile Fault Finding
One of the biggest challenges to car owners in the 21st century is diagnosing faults. As recently as 20 years ago, repairing a car meant finding the problem through a series of checks. Some of these checks might not be entirely reliable and might also necessitate the removal of entire sub-systems, but on the whole it was a simpler process. Cars were largely about the mechanics, which meant no specialist computer knowledge was required.
From around the mid-1990s onwards, this changed across almost all level of mass produced automobiles, and the creep of computerisation and the introduction of sensors and electronic monitoring of components and sub-systems has resulted in a lock-down on what parts can be replaced, and how.
After all, how do you replace a part if you can’t diagnose the fault? Diagnosis these days occurs under the watchful eye of the manufacturer’s team of repairmen, or expensive third parties.
But it doesn’t have to.
What Is OBDII?
Somewhere in your car is an OBDII port, a SCART-style connector that provides a connection to the ECU (engine control unit), and through which diagnostic information (and monitoring data) can be received.
Specification for OBDII states that the port must be no more than three feet from the driver, so look around your gear stick and handbreak, under ashtrays, under the dashboard, etc.
Once found, you can connect an OBDII-compatible diagnostic machine to your car to find the faults. These can be purchased online for around $30 – but a cheaper option to purchase a dedicated cable or Bluetooth device which usually ships with software compatible with your laptop or Windows 8 tablet (such as the Microsoft Surface Pro series).
What this means is that you can repeatedly diagnose problems and monitor your car’s performance! You might even combine it with plans to install a Windows-based carputer, possibly using an old laptop or netbook.
Buying An OBDII Connector Cable
Different car manufacturers use differing protocols for OBDII. Although the physical connectors are the same, the wiring will not be the same for all makes of car.
The solution here is simple: make sure the OBDII connector you purchase is designed for use with your car. You can go online to Amazon and eBay to find a suitable connector, making sure to check in the product notes that it is compatible with your vehicle.
These devices are inexpensive, and as long as you have compatible hardware to run the software, you should be able to diagnose any problems with your car in minutes.
As far as the devices are concerned, however, using a compact Bluetooth OBDII connector is a better option than having cables strewn around the driver’s seat.
Diagnosing Automobile Faults With An OBDII Connector And Diagnostic Utility
To get to the bottom of any faults your car may be showing (betrayed by lights on the dashboard blinking or refusing staying on after ignition) you will need to connect your OBDII device to your computer. The best option for this is with a Bluetooth OBDII device, as mentioned above; just make sure your computer has Bluetooth or you have a Bluetooth USB dongle connected.
Various apps are available for Windows users. You might try the free OBDwiz from www.scantool.net to get the basic functionality (they sell a variety of premium alternatives, including a touch-friendly app) such as a graphical dashboard and diagnostic tools.
Logs can also be kept, but remember data collected is only as good as the sensors in your vehicle, so ensure these are replaced when they stop reporting correctly.
Using diagnostics in any of these apps is a case of switching to the correct mode, running a scan and getting the error codes, which will be displayed alongside the explanation of the fault.
Your Diagnosis Is Made – What Next?
Once you have established what the problem is with your car, you can take steps to resolve it. For instance, my 1999 Vauxhall Zafira recently had a fault with the heater. Without the diagnostic software I may have had to replace the entire sub-system rather than just the fan component.
This was a relatively simple fix, however – other problems may require far more intensive work, for which you may consider getting some assistance with if you’re not experienced with auto repairs.
Have you used a diagnostic application and OBDII cable to help repair your car? Is this something that you might consider trying? Let us know what you think in the comments.
Featured Image Credit: Professional car mechanic working in auto repair service via Shutterstock