Hello,

My knocklite arrived and I'm getting ready to install it in my 2002 WRX. I don't have a separate knock sensor (I'll probably add one later) so I just want to wire it using the stock sensor for now. In one of his original posts Jarrad mentioned that he did all his wiring for his LGT at the ECU. I assume he meant he got the power and ground taps there as well.

I've studied the ECU wiring diagram for the 02' WRX located on North Ursalia's web site (Viewable here) (http://www.northursalia.com/modifications/misc/wiring/wrxpin.html).

My plan is to run all the wires to the ECU and tap the following wires for their respective function:

ECU Connector - Pin# - Content
B135 - (B)9 - Supplies 5V power to several sensors
B135 - (B)4 - Knock sensor signal
B136 - (C)9 - Engine speed (RPM)
B135 - (B)19 - Ground (Sensor)

As far as grounds go would it be better to use a chassis grounding point or tap one of the ground at the ECU?

Would it be better to get 12V power from say the switched ignition power than the 5V power off the ECU?

I just want to confirm with you guys that have installed the knocklight before that what I plan to do will not interfere with any of the other ECU or sensor functions, sensitivity, or accuracy.

Any suggestions, comments, or ideas would be appreciated. Also if anyone who has installed one of these knocklites would care to share their experience I'd greatly appreciate it.

Thanks for your time!

Bump... any help?

I would think if the knocklite needs 12v then giving it 5v won't make it happy.

I tapped my power and ground off an acc line. As for the knock lite messing up the knock signal, it shouldn't as it was designed to work with an existing sensor or a dedicated sensor.

I would only tap the ecu for signal wires and not power and ground. I did this and have no problem with my Dtec and knock light.

^^^ Agreed. You don't want to cause a loading issue at the ecu cause it to not function properly. Just tap you knock signal line there and your rpm if you don't want to do that at the cluster.

Thanks guys. I fianlly installed the Knocklite last night.

I ended up tapping the switched power wire and the ground wire from the stereo wiring harness and knock signal wire and tach wire at the ECU.

Thanks again! :banana: