Had a good nose around old posts and on 22b, but there's a bit of confusion as to how it's best to wire the LambaLink - specifically the signal ground.

I'm installing it in my MY99 RB5 with an AE801 ECU and standard OE narrowband O2 sensor.

Here's my understanding of what the 4 wires are.

Red - This is a +12v ignition feed.

I have an existing feed from the cigarette lighter that supplies my Knocklink and SPA digital dual Oil Temp/Pressure guage. The gauges are protected by a 250mA in-line fuse (from the SPA gauge).

Is it OK to use this feed or am I at risk of drawing too much current through the cigarette lighter wiring?

Black - This is a chassis/engine ground according to the Link manual.

I have ran additional ground cables, but use a common ground under the steering column for my other gauges. Is this OK to use this again or should I use the additional ground feed I've ran to my ECU bracket? or even take the feed and attach it to the engine block? (I've ran ground feeds to this already).

White - This is the signal wire.

From reading old posts, this should be taken directly from the O2 signal wire on the ECU. B136 Pin 21 (Thanks Judge)

Green - This is the signal -ve wire.

Not sure where to run this to. Some suggest engine block, others to the O2 sensor itself another is the ECU return from the O2 sensor

Anyone fitted the LambdaLink themselves?

Stefan

 

Connect the black and green wire's to the same point, suggest NOT using the cig lighter feed as that is susceptible to interferance, use the ecu power feed in the footwell and ground to te lower ecu mounting stud, you can pick up the signal down there as well as you mentioned.

bob

 

Bob,

Do you recommend not using the cig lighter wire for any gauge or just not for the LambdaLink?

Stefan

 

Are the pinouts the same for AE801/802? If so, the signal wire you want is B136 Pin 21 (third row down, third wire in from the right, white with silver specks.

 

Thanks Judge, I've amended the details above.

 

If you go to the ECU for earth and live (I would personally) its B136 24 and 25 respectively.

MB

 

Thanks MB.

What inline fuse should be used on the live feed?

Stefan

 

OK,

I'm going to use the following

Red (+12v ignition) - ECU B136 pin 25
White - ECU B136 pin 21
Black & Green - ECU lower mounting bolt

If I suspect a problem (or discrpency) with the grounding, then I'll tap into the ECU ground (B136 pin 24).

What's the best method (idiot instructions please) to check for grounding differences given a small voltage change will affect the AFR display?

Stefan

 

I would just use the ECU earth wire anyway, I know a couple of people who had problems with the mounting bolt. I think you have an eath mod though dont you? As long as the ECU one was one you upgraded, it will probably be ok...

I didnt use a fuse either

MB

 

Thanks m8.

Yes, I've installed a grounding mod, including one to the ECU mounting bracket. Since a 0.1v descrepency can vary the AFR display output, I'm worried that the earth may cause dodgy readings.

How many wires are on a UK MY99/00 O2 sensor and how are they wired? e.g. if the sensor has earth and signal, do both run directly back to the ECU or is the earth attached to the chassis, zorst, etc..???

My thinking on the bolt was that it's easy to wire up. If I start stripping and soldering onto the ECU wires, it's a bugger to undo and cleanup.

Stefan

 

Got a feeling there are 3 wires, 2 of which being heater, and the other being signal. I think it earths via the thread contact with the exhaust...

 

OK, I'm an idiot when it comes to electrics so how do I go about checking the ground at the ECU bolt and the zorst. I have a multimeter and I'm not afraid to use it

Stefan

 

can someone please point out where this B136 is in relation to the four plugs running out/into the ecu. i am not very good when it comes to wiring so any help would be great!

 

Four plugs? What's your MY?

 

MY96 STi2 - four yellow plugs

 

http://www.ravensblade-impreza.com/m...ring/link5.pdf

Look at the bottom of page 33. You should only have 3 plugs, so it sounds like you have a different ECU. What year is your car?

MB

 

It is a MY96 1995 Wrx Sti v2 and it has four yellow connectors running off the ecu. It is a 6K ecu code

 

Ok, thats different from the link I put up above. Don't know what the numbers are for it though...

MB