Wideband SLC 14point7 LT1 OBD1 $EE Issue

[yoheer]

Hi.
I've just installed a wideband from 14point7 guyz
SLC Free 2 (open source)
https://www.14point7.com/products/sigma-lambda-controller-free-2
It operates with Bosch Lsu 4.9 sensor
"Simulated Narrowband Output allows you to install a Wideband O2 Sensor in place of your Narrowband O2 sensor
Switch point @ 1[Lambda], 14.7[AFR] equivalent for gasoline"
So I made the wiring and installed it instead of my original Left bank sensor. And there is an issue.

[yoheer]

The car is running very rich. But the Left bank BLM is showing lean condition and the PCM is adding fuel till black smoke from the exhaust.
AFR indication seems to be correct (I've checked it in open loop and it is idling AFR ~13 to 16 depending on time after i touched the pedal)
Right o2 sensor works perfect. 0.1 to 0.9 voltage
Left (controller simulated output) is just about 0.3 to 0.4
Who knows, how to make it operate in the right manner?
Is it a faulty o2 sensor? (It is original. I got it used from a junkyard, but it's in good shape and seems to be working)
Or maybe a controller has an incorrect narrowband output algorithm?
I made a short log after BLM reset. WB is connected to D27 pin.
Remove .txt from the file name. It should be "eedata" extension.
The file is in attachment.
Any ideas?

[yoheer]

And SLC has only one wire for the narrowband output. It is connected to pin 'B'
Here is o2 connector. Pin 'A' is not connected now. Should it be? If yes what should i connect there?
http://shbox.com/1/HO2S_connector.jpg


18276

[steveo]

your simulated signal never goes over 450mv. not a good simulator. of course the ECM keeps adding fuel

besides, adding a simulator to one bank of a two bank closed loop setup is incorrect. you should weld a bung in and drop the simulator. it'll NEVER WORK.

[yoheer]

I wonder if pin A requires ground. Simulated output looks like reference voltage. Despite the voltage drop to 300mv
Maybe I have to hook it up to the controller ground. I mean A pin.

[Tom H]

Internally your PCM uses a TI chip to turn the switching of the O2 sensor into a usable digital signal. The chip is LM9044 you can find data sheet for the part if you still need it.

One of the features of this part is "Input open circuit detection". Here is a quote from the data sheet...



The output op amp is capable of driving capacitive
loads and is fully protected. Also, internal circuitry has
been provided to detect open circuit conditions on
either or both inputs and force the output to a “home”
position (a ratio of the external reference voltage).


Here is the schematic for a slightly later PCM, I believe it is the same as yours

-Tom

Edit: I did not know anything about the circuit you have between the wide band and the PCM. It's unclear if this circuit is set up to properly drive the input. You could post details, it would be interesting.

[yoheer]

Edit: I did not know anything about the circuit you have between the wide band and the PCM. It's unclear if this circuit is set up to properly drive the input. You could post details, it would be interesting.

Here is a manual for this device
https://cdn.shopify.com/s/files/1/0189/1312/files/SLC_Free_2_Manual_8084ced2-a6e0-4cb3-986f-526cdb66ab44.pdf?v=1628395906

Source code and pcb files
https://cdn.shopify.com/s/files/1/0189/1312/files/SLC_Free_2_Source_Files_Jan_12_2020.zip?56

Here is the datasheet, but it is for ver. 1. I cant find one fore version 2 like i have
https://cdn.shopify.com/s/files/1/0189/1312/files/SLC_Free_Manual.zip?2648

Here is a link to all the documentation
https://www.14point7.com/pages/software-and-documentation

[yoheer]

Tom H, you're right
I just hooked up low input to ground and thats it

[yoheer]

Finally I welded a bung and got rid of simulation.

[dave w]

Finally I welded a bung and got rid of simulation.:thumbsup::jfj: