Aftermarket Wideband to Rear O2 signal
 

So I've spent the last few weeks tuning my car (or @jamesm tuning it and me trying to learn as much as possible). the process has sometimes been slow by not having the Wideband logged by Ecutek, which means anything below 11.02 AFR is not logged. This makes it hard to know how much fuel needs to be taken out of the tune and be able to reach target AFR's quicker (in summary, spend less time modifying the rom, flashing and more time fine tuning it).

Well @EcuTek responded quickly to the community requests and has provided us a way to log the Rear O2 input which otherwise is useless.

We now can connect our aftermarket Wideband (AEM Failsafe in my setup) to the O2 sensor wiring and have it all together in a nice clean Ecutek log! This also helps verify how well/bad is the stock O2 calibrated.

Below is what I did: (Special thanks to my good friend @jamesm who helped me figure it all out).


James showed me: from page 48 of the ecutek docs. Get that thing wired in and it'll make both of our lives much easier :)

https://www.evernote.com/shard/s251/...-48-of-58).png

Then i started digging into it:

So from the wiring diagram:

This is the A34 connector, and we need to connect to pin 21:

https://lh6.googleusercontent.com/-A....28%2520PM.png

Pin 21 takes signal from the C13 Rear O2 connector, blue wire (see below) #3 on C13

https://lh3.googleusercontent.com/-R....08%2520PM.png


Finally, below is C13, the Rear O2 connector. I'm in the process of connecting the Failsafe White cable (analog AFR output) to pin #3 in C13.

https://lh6.googleusercontent.com/--....49%2520PM.png

This is the table AEM gives for output AFR vs. Volts. :cheers:

https://lh6.googleusercontent.com/-a....07%2520PM.png



DONE!! Wideband is logged via Ecutek. Software update AND tune file update is required. This is only capable in Ecutek RaceRom 7.

Hope it helps!!

Installation pics in the engine bay:


https://lh5.googleusercontent.com/-F...2/IMAG1605.jpg

https://lh5.googleusercontent.com/-Z...2/IMAG1604.jpg

https://lh6.googleusercontent.com/-E...0/IMAG1611.jpg

Awesome! Great work!

I'll add that this opens up a whole new world of opportunity for RaceRom users, not just logging. I've been using wideband input on the CPC voltage line for a while now, for everything from full-time closed loop fuel control (awesome for tuning sd), to AFR target safety cuts (i.e. cut fuel/throttle/timing if AFR misses target by too much at a given boost level). It works quite well, and i have a screencast showing the results of my closed loop fueling tests.

this also allows me to run flexfuel now, so win :).

Apparently the primary 02 sensor isn't a narrowband, but a pretty decent wideband.

Still a 4-wire unit isn't it? True wideband is moar better and has moar wires.

I would consider a nice wideband something that can read from 8-18

It's a planar-type wide-range o2 sensor, not a wideband. It has a narrower operable range, calibrated from the factory to be most accurate near stoich and slightly leaner than stoich. It can be recalibrated to read lower, but accuracy at richer afrs is not great.

100% not useful to me at this point, but awesome for people that need a better wideband signal!!

Good work!

So you need to cut the blue wire from stock rear O2 sensor and connect AEM's white wire instead ?

Yes sir. I cut the O2 cable thus leaving the OEM harness intact.

You will also need to connect the Failsafe brown cable (Analog ground) to ground in order to get the proper reading and that's it. It works beautifully.

Someone make a plug and play!

well that just made wiring this to my P3Cars gauge a whole new game :bonk:

http://www.innovatemotorsports.com/products/lc2.php

Yeah, will be basically the same that was needed for the AM Failsafe.