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As some of you would know from our webinar before christmas, I've been testing out the AEM 4 Channel UEGO on our turbocharged Toyota GT86. The AEM UEGO kit can output AFR via analogue voltage but I was more interested in it's ability to transmit the data via CAN. As part of the install I'm receiving the AFR and turbine inlet pressure (TIP) into my Motec CDL3 dash via CAN. I'm then outputting both pieces of data into the Motec M1 ECU.
The M1 at this point can't receive the data direct from the AEM module as it is quite restrictive in what data it is expecting to see and what address it should be on. For this reason I'm transmitting the data back out of the CDL3 in a form the M1 is expecting to see - In the case of the AFR data I'm replicating a Motec LTC (Lambda To CAN) template.
I've had a few requests for information about this CAN template so thought I would post it here. The Turbine Inlet Pressure template isn't complete as I'm only interested in the actual exhaust back pressure data. If you want all the diagnostics information about the lambda input you could easily modify the template to include this.
Any questions just feel free to ask :)
Thanks for the templates Andre, very much appreciated!!!
Are you running the Lambda sensors in the exhaust manifolds prior to the turbo? if so, is there any compensation being applied to the lambda reading to allow for the variances that can be induced by having a pressure greater than atmospheric applied to the lambda sensors?
Does this template apply to the c125 as well?
Sorry BlackRex, didn't see your question back in February for some reason. Yes we are running the sensors pre-turbo, and yes they are back pressure compensated. This is handled internally by the AEM UEGO module with input from the optional back pressure sensor.
@ Girch, yes these templates will work for the C125 dash too.
Thanks for that Andre
Would we need to run a terminating resistor ? I believe the AEM has one built in.
The C125 Race logging loom has a 100ohm resistor in the loom, if the distance between the two devices is less than 50cm, this should be sufficient, any longer than that then a resistor at each end is recommended.
Well I'm sure I've covered everything, but I can't receive any data from the AEM.
I currently have the template loaded, can hi/Lo is wired correctly.
The AEM is powered via the main harness, maybe I would need to power it up via the can plug?
I would be surprised if it did need to be, but I haven't used these units.
I emailed AEM
The actually recommend to power the unit via the main harness.
Still having some issues with the AEM communicating with the c125.
On can0 the error message I'm getting is 4096. "Bus warning" more than 96 errors
Check wiring and termination resistors ."
So I have checked this all is well, perhaps the AEM having a 120ohm terminating resistor is the issue.
I'm at a loss. Please help!
My AEM UEGO is powered separate to the CAN harness and works fine. Are you seeing the unit physically power up via the status LEDs on the front panel?
I'll assume you've got the unit wired on the correct CAN bus? Sounds simple but I've seen this a few times now so it doesn't hurt to ask :)
The terminating resistor doesn't seem to be too critical in terms of its actual resistance - Some manufacturers call for 100 ohm while others specify 120 ohm. I've used both with no trouble although I wouldn't mix up the two in one CAN bus.
It might pay to just check that you're using extended addressing and the base address is 0000001F. This should be in the template but worth checking. Let us know how you get on.
The unit is powered up. I'm running the AEM via the accessory port on the c125, which is can 1.
I'll confirm the base address and let you know.
Thank you Andre for the template. I get successfully the values on the dash on CAN2.
Now I struggle with setup of C125 communication to M800. I need some kind of live data to equalice cylinders on the dyno.
Is the M800 (v.3.3) set 1 template in the dash manager only setup to receive?
How do I get the cyl Lambda values to the m800?
I found a document for ADL, but I'm not sure if that is still true for C125?
The M800 templates in the dash manager software are simply as receive template and won't actually send any data to the ECU. To send data you'll need to set up a custom template in the dash to transmit the data you want. The pdf you've linked to for the ADL will still work with the C125.
Thank you for answer. I tried the ADL settings short after my post. You're right, it works as descripted in the PDF.
A 100ohm or 120ohm resistor was not needed, regardless the fact the CAN cable to the AEM Uego is aprox. 2m long.
When it comes to CAN bus implementation you'll often find that you can get away with a lot that is outside the recommended best practice, however occasionally you can get tripped up too.