griz

Hi all,
Having some troubles getting this thing to log, uses a Bosch 4.9LSU which feeds to a controller. I'm almost positive I have the 0-5v output in the correct ECU pin (73 for an evo 9) but I'm not sure where the analog output should be grounded. Logs are showing a range of 10-11 with the formula 10+(20-10)*X/255 so I'm thinking it's getting very little voltage.

Any help is appreciated
Thanks

griz

Bump, when I checked with the multimeter the analog output wire is reading around 2.5ish volt with the gauge around 14.7, but that is with the car off...When I start it the readings go crazy even with the gauge reading the same. Thoughts?

WRC-LVR

iTrader: (1)

formula not correct? double check the pin is actually in place and seated. Sounds like a bad contact to me.

griz

Well definitely double check that. When I log just X in evoscan from 3C I'm getting readings of like 21-22

WRC-LVR

iTrader: (1)

Assuming a value of 2.5 V for the output at 14.7 given the 0-5V output, and the range of 0-255 for the 0-5V then your formula yields 10 +((20-10)*((2.5/5) *255)/255. this gives you 10+(10)*127.5/255 or 15.0 AFR

So you should be reading about 15 AFR from the controller thru the ECU.

something wrong in how the ECU is converting the signal or outputting it..

Work around until you get the correct formula....

compare the gauge reading at idle to the reading logging to the screen for Evoscan. Then figure out the correct fudge factor to multiply it by to get the correct readout and plug that into Evoscan. then test it..

for example if the evoscan reading is 20.5 for the real 14.7 then multiply the result by (x*14.7/20.5)

Let us know how that works

qsiguy

Does that model wideband have a simulated output to allow you to wire into an OEM ECU to replace the normal front O2 sensor? My Zeitronics ZT-2 has a simulated narrow band output wire that can be used for that. This analog signal voltage jumps around while the engine is running which might explain your signal voltage "going crazy" after you started the car.

griz

Update since I just found the time to work on it... I think it was pinned incorrectly? The wire in pin 73 is white, correct? And it's in the plug all the way on the right? I have it pinned there now and now I'm getting no reading at all.

merlin.oz

My son has just bought a Prosport wideband, so I have the documentation.

I think the base formula would be
(x/255*5)*2 +10

and simplified EvoScan eval should be

x*0.0392 +10

Evoscan runs better without any divides in the eval.

griz

Does he have it hooked up to the ECU and logging correctly?

merlin.oz

No, he is an STi kind of guy.
But guess who will get the the install job?

griz

Sounds familiar my pops helps with a lot of my installs as well.


Anyway, I have it pinned and definitely seated properly and I'm getting no reading at all from 3C in evoscan... Is this still a hardware issue?

merlin.oz

on the brown wire?

And did you connect the black ground wire to the ECU ground, preferably at the ecu itself?

griz

I believe so, where exactly on the ECU should it be connected?

merlin.oz

Connect the gauge ground wire to ECU pin 34.

griz

No good, still no reading. Wondering if it's rom related