Alright, I decided to stop conjecturing and theorizing about putting a remote start in my 5MT WRX, and did it today. The unit was a DEI model, and also included security and of course keyless entry. I realize this has been done, but the info is scattered and hard to find. Here is some info to help out anyone considering a similar setup:
First, here are the relevant wires and their locations that you'll need:
12V Constant: Black/white -- ignition harness
Starter wire: Black/yellow -- ignition harness
Ignition wire: Black -- ignition harness
Accessory wire: Black/blue -- ignition harness
Door lock wire: red/white -- keyless module* (negative trigger)
Door unlock wire: yellow/red -- keyless module* (negative trigger)
Parking lights: Purple -- harness on front of fuse box
Door Trigger: yellow -- keyless module* (negative trigger)
Dome supervision: same as door trigger
Brake wire: white/black -- brake switch
Trunk trigger: yellow/red -- OEM alarm harness**
Neutral indicator: green/black -- ECU, pin A8***
Tachometer wire: white/yellow -- see ****
Clutch bypass wire: clear T harness above clutch, higher of two
* The keyless module (which is actually the integrated module...see 1/6/05 edit) is directly to the right of the fusebox.
** The OEM alarm harness is behind the glovebox, towards the drivers side. If you have the OEM alarm, it will be plugged into a harness running toward your e-brake. Otherwise, it will be taped to a much larger wiring harness.
***The ECU is under the carpet on the front passenger side. If you're looking at it from the passenger seat, harness 'A' is closest to the firewall, pin 8 is in the middle of the column closest to the firewall.
****Tach wire I used is in a harness just in front of the intake pipe, towards the front fender. Trust me, it's in there.
The only way to integrate the neutral wire is to tie it into the hood pin shutdown wire. It CANNOT drive a relay, so don't even try. (I did...) It is imperative to diode isolate it from the hood pinswitch. Wire the diode with the stripe towards the ECU, so it can only pass negative current, which is what the wire transmits when the car is in gear. It works beautifully.
NOTE: APPARENTLY, ON 2005 AND UP MODELS THE POLARITY IS OPPOSITE OF WHAT IS DESCRIBED HERE! BUT YOU ALREADY KNEW THAT BECAUSE YOU'RE TESTING ALL OF YOUR WIRES WITH A DMM, RIGHT???
To bypass the clutch, use a relay as follows: Pin 85 - (-) trigger for starter wire coming from the remote start relay pack. This is the small gauge wire, not the large guage. Pin 86 - Constant, fused 12V. Pin 30 - One of the wires in the aforementioned T connector at the clutch. Pin 87 - The other wire at said connector. It doesn't matter which goes where, because the point is only to connect them while the remote starter is cranking the starter. Doing it this way is 100% safe, because there is NO way to start the car without either having the clutch in or remote starting it in neutral.
As usual, attempt all of this at your own risk. You can damage the cars circuitry if you don't know what you're doing. Also seriously consider taking these notes to a reputable dealer to have it installed professionally.
Thanks to northursalia.com for the ECU pinouts.
Please feel free to add anything or ask questions.
Edit: This was done on a MY02 WRX sedan. Many of the wire colors will be the same on the rest of the Impreza line, but I'm not sure about the tach wire and neutral wire. Also, unless you installed the OEM trunk light on your RS/TS/OBS, there will be no trunk wire.
1/6/05: Thanks to tegnwrx for pointing this out: The keyless module is actually above the fuse box; the module to the right (which is where all your wires are) is the integrated unit. It is okay to remove the keyless module if you will not be using the OEM keyless/alarm (and it frees up some great real estate!), but DO NOT remove the integrated module.
MY08 info courtesy of Chp_Stix:
FYI DEI's Canadian Web Site is only goes to 2006 Imprezza's
Got the alarm/starter combo in without a hitch.
For the key by-pass I made my own 556UW to Transmit the signal and it worked fine,
Got a few extra wires this year and all has changed colors since previous years pretty much... but it was fun and I nailed it first round. So here is the tech info....
Disclaimer (If you dont know how to do this or dont have the right tools lets a pro do it. This is only a guide please take the time to actually double check the wires yourself. Never take tech info as the deffinate there is often multiple wires of the same color code and if you use the wrong wire and send a + or - signal through it you risk fry-ing your ECU)
I wont detail how to remove panels since if you dont know how to do that you probably shouldnt be installing this in your car yourself.
Wire Color Guide:
12V - White
Starter 1 - White Black
Starter 2 - White Red (You need both for remote start)
Ignition - Green
Accy 1 - Yellow (Radio and Heated seats)
Accy 2 - Blue (Heater)
Negative Parking Lights - Black White (at switch)
Brake - Brown/White (At Switch)
Locate BCM (Above Gas pedal)
All found in blue plug on the end of the module
Lock - Lt. Green
Unlock - Blue Black
Door Pin - Blue Orange with two silver dashes
Located in cluster
Tach - Grey Red (there is only one plug in the back of the instrument cluster)
Hatch will unlock with regular unlock
Factory alarm disarms with factory remote only
This was done on an Auto so no park-brake or clutch info yet sorry
Hope this helps someone, I will post pics of the BCM tomorrow