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Discussion Starter #1
I just purchased a knocklite and I need to find the RPM signal wire and the knock signal wire on a 05 FXT ECU. Anyone know this information?
 

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Mr. April 2008, Image Master
2005 X
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1,325 Posts
The tach wire should be the solid green wire on the back of your cluster...
 

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Premium Member
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Discussion Starter #3
I was hoping to tap at the ECU side since I need to tap the knock wire there also.

The Wraith said:
The tach wire should be the solid green wire on the back of your cluster...
 

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Mr. April 2008, Image Master
2005 X
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1,325 Posts
All right wait for peaty or other gods to chime in. They know all :bow, down:
 

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Premium Member
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Discussion Starter #6
You know, I am afraid the tap will cut the wire.. Hehe. I'll try to be careful. The correct way to splice would be to cut the jacket with a razor and solder the new wire on but thats pretty permenant.

sirwilliam said:
Just remember, "Don't cut the red wire.":lol:

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ZuMBLe said:
The correct way to splice would be to cut the jacket with a razor and solder the new wire on but thats pretty permenant.
That is the best way for sure. That is how I installed my SplitSecond Fuel Timing Calibrator (piggyback computer for fuel injector control) on my Toyota.
 

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Discussion Starter #8
So you're saying I should do it this way? I guess I'll have to go in there and see what the wires look like etc. I still need to know which wires to go after though.

MountainBiker said:
That is the best way for sure. That is how I installed my SplitSecond Fuel Timing Calibrator (piggyback computer for fuel injector control) on my Toyota.
 

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There are alway these tap in thingys, but they can cause damage to the wire, and they may also generate some resistance.

I'd suggest carefully using a blade to remove 1/4" or so of the insulator, then wrap your wire around it and solder. Then use some good electrical tape around the joint.
 

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Discussion Starter #10
Yeah, what you described is the best way really so there won't be any malfunction due to vibration etc.

MountainBiker said:
There are alway these tap in thingys, but they can cause damage to the wire, and they may also generate some resistance.

I'd suggest carefully using a blade to remove 1/4" or so of the insulator, then wrap your wire around it and solder. Then use some good electrical tape around the joint.
 

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Asphalt Surfers Unlimited
2004 Forester XT
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742 Posts
Here's a PDF document that will help you with any ECU-related wiring that you may need to do. This is directly from the '05 Forester service manual.

RIGHTCLICK -> SAVE AS and view locally to save my bandwidth (file is 750k)
http://webpages.charter.net/drifter/files/fxt_engine_electrical.pdf

The Turbo engine wiring section starts on page 13 (WI-46).

The four main connectors on the ECM are A (B134), B (B135), C (B136) and D (B137).

Schematic views are from the ECM SIDE of the plug, not the wiring side.



Wiring color codes:

L Blue
B Black
Y Yellow
G Green
R Red
W White
Br Brown
Lg Light green
Gr Gray
P Pink
Or Orange
Sb Sky Blue
V Violet
SA Sealed (Inner)
SB Sealed (Outer)

Double codes (i.e. YB) indicate the primary color with the first letter and the stripe color with the second... in this case, a Yellow wire with a Black stripe.

Hope this helps!
 

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Discussion Starter #12
Thank you!!! I'll have to do some studying of the diagrams now.. =)


Porter said:
Here's a PDF document that will help you with any ECU-related wiring that you may need to do. This is directly from the '05 Forester service manual.

RIGHTCLICK -> SAVE AS and view locally to save my bandwidth (file is 750k)
http://webpages.charter.net/drifter/files/fxt_engine_electrical.pdf

The Turbo engine wiring section starts on page 13 (WI-46).

The four main connectors on the ECM are A (B134), B (B135), C (B136) and D (B137).

Schematic views are from the ECM SIDE of the plug, not the wiring side.



Wiring color codes:

L Blue
B Black
Y Yellow
G Green
R Red
W White
Br Brown
Lg Light green
Gr Gray
P Pink
Or Orange
Sb Sky Blue
V Violet
SA Sealed (Inner)
SB Sealed (Outer)

Double codes (i.e. YB) indicate the primary color with the first letter and the stripe color with the second... in this case, a Yellow wire with a Black stripe.

Hope this helps!
 

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Registered
2004 Forester XT
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291 Posts
ZuMBLe said:
I just purchased a knocklite and I need to find the RPM signal wire and the knock signal wire on a 05 FXT ECU.
Zumble I did this EXACT install just last weekend. I picked up the relevant wires at the ECU - a little finicky, but certainly possible.

Please advise your email address and I will send a document detailing all the ECU pinouts, and some voltage info for verification.

Cheers
Andrew
 

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Can I get some feedback on the effectiveness of the knocklite ( I use a knocklink already ) ?

Are you using a seperate knock sensor or the ecu's ??? I was under the impression that using the factory knock sensor for this was a bad idea ...


Cheers
Steve
 

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Premium Member
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Discussion Starter #15
I haven't done my install yet but I'll give you some feedback based on my research. People who use knocklink then knocklite usually prefer the knocklite. The knocklite setup involves teaching the car what the engine sounds like at different RPMs. You can also adjust the sensitivity. The LED is multi colored so you can differentiate moderate knock to severe.

I'm going to use the stock sensor. PDX Tuning does this with their knocklite installs so I think it's okay. The precaution I'm taking is using a shielded knock signal wire. I replaced the factory wire with a shielded twisted pair wire.



stevem said:
Can I get some feedback on the effectiveness of the knocklite ( I use a knocklink already ) ?

Are you using a seperate knock sensor or the ecu's ??? I was under the impression that using the factory knock sensor for this was a bad idea ...


Cheers
Steve
 

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2004 Forester XT
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291 Posts
stevem said:
Can Are you using a seperate knock sensor or the ecu's ??? I was under the impression that using the factory knock sensor for this was a bad idea ...
Steve, I'm using a TurboXS Knocklite and was advised that the factory knock sensor was suitable - I only put it in a week ago, so I'm still learning it (and learnin' IT)

Cheers
Andrew
 

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Problem as I see it is that I can see 'crackles' on the KL (confirmed with det cans) without the ecu reacting with -ve KC on deltadash - now is this a function of the ecu or a limitation of the OEM knock sensor ?


Steve
 

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Premium Member
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Discussion Starter #18
There is possibly a threshold you have to pass for the ecu to react. Maybe these crackles aren't strong enough? I would think it's a ecu issue rather than a knock sensor issue.

stevem said:
Problem as I see it is that I can see 'crackles' on the KL (confirmed with det cans) without the ecu reacting with -ve KC on deltadash - now is this a function of the ecu or a limitation of the OEM knock sensor ?


Steve
 

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Premium Member
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stevem said:
Problem as I see it is that I can see 'crackles' on the KL (confirmed with det cans) without the ecu reacting with -ve KC on deltadash - now is this a function of the ecu or a limitation of the OEM knock sensor ?
Pay attention to what RPM this happens at. Most ECMs ignore knock sensor input except for a portion of the rev range. This is to avoid getting false positives due to engine noise.

I know for a fact that my Toyota Tacoma only listens to the knock sensor at 3k rpm and above. I suspect my Forester does the same thing, because I can get audible knock below 3k, but not above.
 

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Problem with the subaru factory sensor is that it *stops* listening at 5500. It certainly listens down low as you can get immediate -ve kc if you mash the throttle. A 'roll on' with the foot doesn't have the same effect btw.
 
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