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Bugeye WRX, '00 RS Rally Cah'
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Discussion Starter · #1 ·
I have been searching for information as to how to install a digital gear indicator in my rally car. I found tons of people willing to ask why I would want to do it but very little help on getting it done. :bonk: Here is my write up on my installation (can be found here: » Digital Gear Indicator install with images). Hope it helps someone.

First, I removed the panel I needed to in order to access my ECU. Then I decided that I was just going to use vampire clips to tap into the wires that I needed. The documentation that came with the gear indicator said to solder the connections... I didn't listen. Directions? Who needs directions? After about 2 hours I determined they were right and I restarted the install and had some success.

Follow the typical recommendation of Subaru and disconnect the battery before doing this work.

I am not responsible if you blow up a car (yours or someone else's).



This is a rally car. I have very little coach work (aka: almost no plastic stuff inside the car). Removing panels really isn't necessary for me to get to the ECU or anything else for that matter.

I know how to solder, use heat shrink, and understand electronics. If you don't know how to solder correctly or understand the damage that can be caused by passing too much heat through electronics... don't try this.

The unit I bought (DATATOOL » Support) had a the following connections and associated color codes

Black; Electrical ground
Red; 12 volt switched
Yellow; Engine speed pulse (RPM)
Green; Speedometer pulse (MPH/KPH)
Brown; Neutral switch (there are units that don't have this connection)
Orange; Learn/set up

I found that the signal from various sources will induce itself into the tach and speedo signal cables. Fans, ground loops, engine noise, etc. Running the power, ground and signal cables to the ECU eliminated this issue for me.


Get all the stuff you need to do the installation. Wire cutters and strippers, soldering iron and solder, heat shrink tubing of various sizes, screw drivers, prying tools (for panels), and a BFH (just in case). I purchased a Datatool Digital Gear Indicator through <a certain online retailer that starts with and A and ends in a zon> for about $80. There are plenty out there for more/less with varying levels of features.

Since these things are designed to go onto motorcycles (for the most part) the wires are only about 2-3 feet long. If possible, get wires to extend the ones from the unit to the ECU that are the same color as the ones on the DiGI. By this I mean get a yellow wire to extend the yellow wire on the Digital Gear Indicator through the expected route to the ECU.


1. Determine where you want this thing to go. I chose the front of my dash where it meets the windshield. It offered the best viewing and cleanest install location for me. I would also advise checking it out at night to be sure you don't have the reflection coming off the windshield and obstructing your view of the road.

2. Bust out the soldering iron and extend the wires off of the unit (about 6 should do the trick but measure it first). Be sure to use heat shrink on the connections. The orange and brown wires won't need to go over to the ECU so just make them long enough to reach to the floor.

3. On the top of the dash, up by the windshield, there is a panel that the VIN plate is riveted to. By slipping a flat piece of plastic or a screwdriver underneath it, you can pop it off. Your removal might be slightly different. When your get this panel off, you will see there is opening or a hole where you can pass the wires through the dash and drop them down to where the pedals are. This is where you are going to want to feed your wires if you are mounting on the dash in the same location as I did.

4. Connect the brown wire to the safety switch on the clutch pedal. Looking up under the dash, you will see a connector attached to a switch on the clutch pedal assembly. When the clutch is pressed down, the switch closes and sends a ground signal to the ECU telling it that it is safe to start the car. Tapping into that wire (not sure which one) will supply a switched ground needed to tell the gear indicator when you are between gears. The best way to find this wire would be to pull the connector off and use a multimeter to determine if there is continuity between the chassis and the wire. If there is... it is the other wire you want to attach to.

5. The orange wire is only used for programming. You can strip the casing off the end of this and touch it to a grounding source to do the programming or solder it to a momentary switch and a ground source if you want to make it easier to reprogram like I did.

6. After uncovering your ECU (located on the floor just under the dash on the passenger side). Locate the pins on the ECU that you need to connect to. Based on various sources, I came up with the following pinout of my ECU and the connections I needed to use.

<check for the picture>

Connection Connector-pin # ECU wire color
Switched 12v B135 - 7 Green w/ red stripe
Speedo signal B135 - 24 Green w/ yellow stripe
Engine Speed (RPM) B134 - 30 Light blue
Ground B134 - 35 Black w/ yellow stripe

7. Trace the wire from the ECU out for about 6-8 inches for each connection you are going to make, cut the wire and solder in your DiGI. Friendly reminder...put the heat shrink onto the wire before you solder everything up.

8. Check all your connections and reconnect the battery.

9. Test it out using the instructions included. This would involve driving around in all 5 (or 6) gears while getting the RPMs up to 2k. Give yourself some room.

10. Provided everything worked OK, button up the panels and enjoy. If it didn't, check the connections, re-route the wires, or re-read the manual. Most likely there is some sort of loose or incorrect connection.


Pinouts for the different Subaru ECUs Wiring Diagrams And ECU Pinouts

Pinout for the cluster if you want to connect there instead of the ECU... I didn't try it.

Gear Indicator install in a Honda - different type

LED Gear Indicator Install into CRX/EF Civic - Honda-Tech
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