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Scan Tool

I’m getting to the point where I want to be able to get into my car’s brain a little bit more. I think I need some kind of gizmo that plugs into the car’s computer. I’ve seen a wide range of products at different price points. What do you think of these tools? What features are the most useful? Is there a particular scanner you would recommend?

I like the free scans from an auto parts store best!

For less than $200 scan tools are available which give live data.

Being able to interpet what you see is important, what level are you at?

Yeah, that’s a beautful thing. But I want to dig in a little more. I want to monitor my fuel trim. I want to see a graph of my throttle position and overlay my O2S voltages. Stuff like that.

It depends on how far into diagnostics you want to get.

You can purchase a simple code reader for less than $100.00 and be able to pull generic codes from the computer, or you can purchase a scanner or a scanner program for a laptop that provides a lot more features.

A code reader is just that. It reads the codes, provides a code number, and maybe a brief description of the code. And it may only be able to pull generic OBDII codes. These are the codes that start with P0XXX. A code reader may not be able to pull history codes. History codes are those that the computer stores when the Check Engine light comes on and then turns off. A code reader may not be able to pull pending codes. Pending codes are those that the computer stores when it detects a problem, but the problem hasn’t occured often enough to cause the Check Engine light to come on. A code reader may not be able to display freeze frame data. Freeze frame data is the operating parameters recorded at the time the Check Engine light came on. And a code reader can’t do real-time diagnostics. Real-time diagnostics is where various sensors can be monitored for their values during operating conditions.

But a scanner or a scanner program can do all the things above plus more. How much do you want to spend? And far into diagnostics do you want to go?


Not sure how to answer that, oldschool. I don’t really expect to understand everything. That’s why I want to play around with it. I’ve backprobed enough sensors to know that it can be a pain in the butt - especially when a computer is already conveniently in place keeping track of all that data for me. I just need a way to read it.

I was thinking if you want to do things like make conclusions based upon fuel trim codes or moving into other modules and commanding different function to move through their range. I myself have never tried a PCM reprogram at home or a BCM reprogram at home (after a security system component replacement). Perhaps you want a scan tool that has the ability to act as a event recorder and capture what is happening when an issue pops up.

The scan tool will not replace the DMM and the knowledge required to interpet what it is telling you an using a scan tool for AC pressures would not be my first choice but I think some manufactures want this to become the norm.

Since I know the GM Tech II the best it would be fun to play around with a Tech II and a GM vehicle, but I have neither.

For $400 you can get:

I got one a few weeks ago and love it.

For about $100 I picked up an OBDlink from It works off of a laptop so it isn’t stand alone. It comes with a very basic software that does all of those things you mention. But you can also upgrade the software to do more/expand.

If you have a laptop computer, even an older $100 one running Windows 98 ($50?) you can buy a cable and software that lets you do the things you wish for less than $40 on ebay.

In eBays search window,type USB OBD-2 cable and see what pops up…They usually come from China, takes 10 days, mine works great!

The laptop needs a USB port and a CD drive to load the software…

I have a Snap On Solus. 3500.00