How To Read a Check Engine Light
All Vehicles Built Since 1996
Posted June 27th, 2007 by TheProfessor
Get: A 'Check Engine Light' may mean serious trouble. But don't worry—there are a number of affordable tools on the market that allow you to scan the engine's computer. In this episode we show you how to use DriveRight's CarChip to read and clear an engine code.
Highlights
Your car has many computers including one to control the engine and its emissions. After 1996, all car manufacturers started using a standard system (On Board Diagnostic, second generation or OBD-II) for these engine computers. This was done so that repair shops and emission inspection stations could use the same tool to diagnose and service a variety of cars. While professional equipment is more advanced (and expensive) you can get your own diagnostic tool, or code reader, for a lot cheaper than you think.
How much does your garage or dealership charge to read a simple check engine code? Probably close to what it would cost to buy one of these OBD-II readers! The most common thing you hear from people who purchase the tool is that ‘it pays for itself’ after one or two uses.
What You'll Need
Before you click on the link above and order a CarChip take a moment to think about what kind of information you want from your engine. You probably fall into one of these three categories based on your budget and interest:
- Casual code reader
- Dabbling datalogger
- Horsepower Junkie
Casual Code Readers: you want to purchase a code reader that will read an engine code simply and quickly, and then display the result on a small screen. These types of code readers are convenient because you can keep them in a glove box or toolbox. Click on the links below to explore some of the highest rated diagnostic tools.
Dabbling Dataloggers: you are the type that wants a little more information like throttle position, air intake temperature or fuel trims but you don’t intend to change these parameters or retune the engine (at least not yet!). I chose to review the CarChip because it’s unique and fills the gap between simple code-reading and serious retuning.
You also fit into this category if you are paranoid about other people, such as mechanics and valets, driving your car. In one case, my CarChip recorded all of the details as an inspection mechanic took the Mustang for a 70+ MPH joyride.
Lastly, for all of the lucky parents that have a new driver on their hands: the CarChip will be there to monitor his or her driving habits when you can’t.
Buy the CarChip
Horsepower Junkies: you want to be able to change that “conservative” engine tune on your ride and extract hidden power. If you own a Ford I recommend you purchase an SCT Tuner at AmericanMuscle.com
These tuners let you reprogram the engine computer and can record many parameters at once with high sampling rates. Better yet, Mustang owners get their tuners pre-loaded with a custom tune. Just tell the folks at American Muscle what modifications you have on your Mustang and they’ll do the rest.
Additional Tools: the CarChip requires a computer to read the recorded data. The series of SCT Tuners does not require a computer to retune but you will need one if you're a car nerd and like to chart your car's data on Excel. If you have a laptop the SCT Tuners can display real-time data for your copilot. Your computer will need a USB port to connect to these devices.
Applications
The information in this article and video applies to vehicles made after 1996. There are some exceptions. Some Volkswagen and Audi owners will need a special code reader—ensure that the device you purchase can read trouble codes from these vehicles. If you are considering an aftermarket tuner for your vehicle but you don't have a Mustang or other Ford vehicle type in you car below with keywords like "performance chip" or "code reader" and do a search. There are custom tuners made for diesel vehicles, Hondas, Subarus and many others.
Notes and Warnings
Just because these tools give you the option to clear check engine codes doesn’t mean that you should continue to ignore the problem.
Tips, Tricks and Other Resources
If you would like to learn more about OBD-II systems or automotive electronics there are a number of resources. The OBD Clearinghouse will give you an idea of where to look for the OBD-II connector on your car. If you would like to read more about the OBD systems or the science behind tuning engines please consider one of these books below. Those interested in turbocharging or supercharging their engine should, without a doubt, pick up Maximum Boost. I learned a great deal from that book. No matter what keep learning (and watching!).
