Terratrip DSI Probe Tap Point on a US 2002 Subaru WRX

Due to the large number of problems that Neil and I had with finding the correct tap point for Terratrip's DSI probe, I decided to create this page, with pictures. Hopefully, it'll help you with this annoying issue.

If you're not familiar with what the DSI probe is, you should read my info page on the DSI Probe. This contains a picture of the probe, plus pinout info.

The location where we decided finally to tap the DSI probe is at the point where the spedometer/odometer information comes out of the transmission. There may be other points where you can tap, however, we were not successful with tapping anywhere within the guage cluster. To find the location of the tap point near the transmission, you should view the following pictures.

Here are two images of the engine compartment area. Click on the image to bring up a larger more detailed image.

As you can see, I've circled the area where you should investigate to find the tap point for the probe. In the following image, I've got a closer look at this area.

As is fairly evident, the location for the tap point is behind the intercooler. What isn't evident is the actual point itself. The following two pictures shows the actual tap. Note the dip stick on the pictures. You can use this as a reference.

In these two pictures, you can see the actually tap connection in relation to the transmission. Notice that it taps into a plug coming directly out of the transmission. In this plug, there are 3 wires, one of them which is solid green. You want to tap this solid green wire and bring it to pin 5 of the DSI Probe (pin 5 of my description).

To tap into this, you want to use a wire tap which can be purchased from Radio Shack. The item is catalog number 64-3053 and is called a Low-Voltage Tap-Ins, 22-18 guage. This is an easy to use tap, and contains instructions on its usage on the back of the packaging.

Now, after connecting this tap, connecting the other end of the tap to the DSI probe, and connecting the DSI probe to the Terratrip, you now need to calibrate the DSI probe. Note on my DSI Probe page there is a very small little box with a screw. This is the adjust screw. According to Susquehanna Motor Sports you want to use this adjust tool by doing the following. While driving and having the rally computer on, set the Cal factor to 0100. Then, adjust the screw all the way clockwise. While watching the rally computer, watch for when the computer begins to count pulses. At a cal factor of 0100, every pulse is counted. When the rally computer first beings to count, note the orientation of the adjust screw. Now, continue turning the screw until the rally computer stops counting, and note the position again. Orient the Adjust screw midway between the two positions where the computer began and stopped reading. Now, the probe is adjusted.

I really hope this has helped some of you with getting the probe up and running. Have fun rallying!