Now that we've got the hardware configured, it's time to install the scanner software on the laptop. The small CD that comes with the ELM327 scanner has an assortment of compatible software. Unfortunately the only one that's free and not a demo is ScanTool.net for Windows v1.13, and it is very basic. You can scan for codes, clear codes and turn off the check engine light, and see several pages of sensor data. Here's what it looks like:
After looking at the other software on the disc, nothing really caught my eye. But I found a program on the web called TouchScan (ScanTool.net LLC - TouchScan OBD Software - ScanTool.net
) that looked promising and they had a fully functional demo available for download. The demo only works for 14 days but that was plenty of time for me to evaluate it. TouchScan can not only retrieve diagnostic codes and clear them, it can also display a multitude of sensor data, real-time stats, freeze frame data, and vehicle information. There is also a dashboard mode which you can customize to show whatever gauges you want. But the best feature for me is the ability to record your test drive and play it back in real time!
After installing and running TouchScan, you will be at the setup screen. The easiest way to connect with the scanner is to click on AutoDetect. This will scan all COM ports until it finds the scanner. Next it will cycle through the various baud rates and protocols and display the results. In my case it found the scanner on COM5 and connected at 115200 baud using the ISO 15765-4 CAN 11 bit protocol. Apparently, that's the language the RAV4 speaks. After the AutoDetect finishes, simply click Connect and the red bars labeled Interface and ECU should turn green:
Now you can go to the dashboard and give it some gas and watch the gauges go up and down:
As I mentioned, the dashboard can be configured any number of ways:
So, what about reading trouble codes? To test this, I unplugged the MAF sensor on top of the air cleaner box. Started the engine, and it immediately died. Started it again and it ran but the CEL, TRAC, and VSC lights all came on:
I turned off the engine and plugged the MAF sensor back in, but of course the lights stayed on--the codes had been stored in the ECU. At this point I chose Diagnostics on TouchScan and it showed a P0102 and a P0113:
Then I looked at the Freeze Frame Data. This is a snapshot of what exactly was going on when the code was set. As you can see the engine was cold (118F) and the code was set 0 seconds after starting:
If this code had been set while driving, you would know exactly when the problem occurred, at what speed and RPM it happened, and lots of other data that is shown on that screen when you scroll down. So then I clicked on Clear Trouble Codes and the lights went out and everything was back to normal.
But the Record function is what really impressed me about the software. I was idling in the driveway ready for a little test drive. I clicked on Record and away I went:
After driving around for about 12 minutes, I returned home and clicked Stop. What I got was a detailed record of what was going on with the RAV for that drive. I disconnected the BT link, turned off the car and went inside with the laptop. At the kitchen table I clicked on play and I could see what was happening during my test drive in real time:
It was like analyzing a black box from an aircraft. I could switch between screens and see the gauges and sensor data changing as if I were still driving. Pretty cool!
Here are a few more of the information screens:
A couple of things about this setup. When you're finished, don't just close the TouchScan software. Go to Setup and click on Disconnect first. This releases the COM port from the program--if you don't do this and then try to connect again, it will show your COM port is already in use and the connection will fail.
As for the TouchScan software, it seems like a pretty good deal to me. They are selling the full version for $24.95 on their web site with unlimited upgrades. I'll probably get it unless I find something better.
So if you're looking for a inexpensive way to read diagnostic codes and help with troubleshooting engine problems, I recommend this setup highly. It gives you all the information you need and more, and for around 40 bucks you can't go wrong.