Engine Management Light

When the Engine Management light illuminates on the dash for your car it can be very frustrating. Checking the service manual of your car will only give a very vague explanation of the cause and will tell you to get it checked at a garage. Taking a vehicle to the garage just to read the DTC (diagnostic trouble code) can be expensive and time consuming. The actual fault might be something small and cheap to replace that you could possibly do yourself. The DTCs on your vehicle can be read through the OBD connection on your car.

OBD Connection

OBD stands for On Board Diagnostics and provides access to information about the vehicles internal sub-systems. OBD-II or OBD 2 is the latest standard and most vehicles are fitted with that connection. In most vehicles the OBD connector is located underneath the steering wheel near the fuse panel of the car. This connection provides access to data from the vehicles Engine Control Unit (ECU) and is a valuable sources of information about what is going on inside a vehicle. The information it provides contains DTCs, engine data and sensors data. This allows the owner or mechanic to debug faults with the vehicle much easier.

Fault Code Readers

To read DTCs you can use a Fault Code Reader Unit, an OBD to USB cable connector or a Wireless OBD connector.

Fault Code Reader Unit

This is an all in one unit that plugs into directly into your can and displays information on the units screen. This is probably the quickest to get started as its a plug and play unit. The only issues with these is that they can be difficult to use and depending on the product the user interface can be limited in what it displays.

OBD to USB Cable Connector

This cable contains a OBD connector on one side and a USB connector on the other. This means that you can plug it into you PC or any device with a USB. You will need to install software on your PC to be able to read the codes.

Wireless OBD connector

This connector is a small unit that plugs into the OBD connector and transmits the data using either Bluetooth or WIFI. These connectors are the most flexible connector as it can communicate with a wide range of devices including PCs, Laptops, Mobile Phones, IPhones and IPads. These can be got on Amazon for around $20. 

Some wireless OBD connectors come with software apps for phones but I recommend downloading the Torque Pro app for Andriod or the DashCommand app for iOS. These app are cheap and contain a lot of really cool features like engine stats and extensive fault code information. They also display the information on a clear and easy to use user interface.

Before you purchase anything make sure your phone is compatible with the app and that the app is compatible with that OBD connector.

Reading Fault Codes

Before you start debugging fault codes its a good idea to reset all the current fault codes on the vehicle. The reason for this is that some of the codes may have been thrown months ago and are not longer an issue. After you reset the code drive your vehicle until the error lights come back on your dashboard. This time when you read the codes they should be the actual faults that caused the light to Engine Management light to come on. 

When you read the fault code the app should give you information about what the code means and where the fault is on your car. This should help find the exact fault or at least narrow down the possible cause of the fault. Knowing the fault code is still very useful if you need to bring the car to the garage as its easier to price the work being done and prevents mechanics changing parts that did not need to be changed.

WIFI OBD-II Connector