AEM AFR meter as second lambda

[scoobyman]

Good day everyone,

I have purchased myself an AEM wideband uego AFR Meter to monitor AFR in my 4th runner (the troublesome one), while my Motec's lambda is installed in the downpipe.

And i was just wondering, since AEM meter features a Bosch LSU4.2 sensor and has a 0-5v output, would it be possible to make AEM's output work as a second lambda for logging and possibly even run it as second lambda for AFR control?

I wired everything in today, only to find that i do not have dual lambda enabled in my ecu and i do not want to purchase the option before i am 100% sure that it will work.

Cheerios

[Pavlo]

You should be able to log it fine if wired to a 0-5v input. You will not be able to do any closed loop correction using the closed loop lambda system though. I would be wary of the accuracy of the sensor due to the back pressure.

You would be much off to monitor the knock on cylinder 4 using the knock board.

[stevieturbo]

Just wire into LA1 or LA2, whichever is free and calibrate both so they read mixtures within your chosen range.

After calibration, test to ensure both your AEM and as viewed in Motec read the same.

[scoobyman]

Thanks guys,

It's just slightly confusing, as internal lambdas have heater output, Current reading on B26 and voltage reading on B25.

This AEM system has it's own calibration and heater setup, so i am only using the output in volts, which will not correspond to any real values as Motec doesnt know the amps and i cannot calibrate the sensor via Motec?

Is there a lambda setting in Motec where i could simply type in the voltages and enter the corresponding lambda values ? Can it be done in a Lambda characteristics table by using Lambda 2Vs channel and associating those values with lambda readings? I looked through the webinar but it mentioned none of this.
Otherwise it just doesn't look like it will work.

[stevesingo]

Can you not just go into "sensor set up" and input a user defined calibration which matches the AEM 0-5v calibration?

[scoobyman]

EDIT: I found the calibration number on the sensor itself, but it seems that the AEM system is set-up differently and the AEM unit's output is set within the unit itself and is not at all influenced by the sensor's calibration number.

The output voltages are defined by this table of output voltage vs lambda values. So it seems that the only way to get it right, is to make a matrix of voltage vs lambda in the Motec itself.

[scoobyman]

Ok i have now found out that the AEM's output voltage can be modified in a certain way as well.
Is any of these options applicable to motec ?

[scoobyman]

However, reading the helpfile in Motec, it seems that Lambda characteristics can only correlate to current (which is the LA1P or LA2P channel) and not voltage. Looks like it cannot be made to work if i am only using the LA2S channel


Motec's actual help file

"NOTE: THIS TABLE MUST BE FILLED OUT

This table defines the relationship between the normalised sensor pump
current (Ipn) and Lambda.

Normally the following table should be used:

Ipn -5.000 -4.000 -3.000 -2.000 -1.000 -0.500 0.000 continued...
Lambda 0.673 0.704 0.753 0.818 0.900 0.948 1.000 continued...

0.500 1.000 1.500 2.000 2.500 3.000 4.000
1.118 1.266 1.456 1.709 2.063 2.592 5.211

NOTE: The axis channel must be 'La1 Ipn' or 'La2 Ipn' as appropriate.

To select the channel and set the axis values select 'Axis Setup' from
the Tools menu. This allows the Ipn numbers to be entered. The Lambda
value may then be entered into the table."

[scoobyman]

It seems that the only way for me to do what i want, is to splice the actual lambda wires or the wires that connect from lambda to the AEM's input and run them to Motec as well, which is a shame as i do not want to do that.
If anyone thinks there is another way, please let me know.

[stevesingo]

Try this...

Sensor setup

Input Setup

Select La1 and click change

Input Source=Select the AV input you are connected to

Calibration= Wideband Lambda 3 decimal places

Click the custom table option

Open the table and input your voltage output table from your AEM.

HTH

Steve