Open pins for brake pressure and oil temp

Discussion and support for MoTeC's previous generation ECUs.

Open pins for brake pressure and oil temp

Postby Richard0990 on Tue May 03, 2022 4:43 am

Following a choice to add a brake pressure sensor and potentially an oil temperature sensor to my car I looked into the
Ecu for the used channels and then pin out diagram to try and find a spare way,

Now I think I’m confusing myself but also the Ecu has been used on two cars and potentially the tuner hasn’t cleaned up the unused channels since the changes were made, I say this because I cannot get a match between the outputs and then the pin setup pages one says that pins are allocated and then other says not!

I have looked at the logged data to see if I’m getting readings from the channels to add up what is live and what is not. Would it be safe to “assume” I know that this is dangerous that if the out put say AT3 is shown in digital input functions as gear ign cut but in input setup it doesn’t feature at all on any page and the data has a straight 0 all through the run that it is not used and can be wired for a pressure sensor? To make this a little bit harder all of the ecu plugs have wire in! So it’s not like I can clearly see that it’s an old feature and not used as it is wired in the ecu plug end anyway!

Would it also be safe to say then that if it doesn’t feature in the input pin setup box that it isn’t used currently when running the car and can be changed as desired? And potentially the only pins that are used are in the box with allocated inputs?

Any guidance would be greatly appreciated

Thank you
Richard0990
 
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Re: Open pins for brake pressure and oil temp

Postby David Ferguson on Tue May 03, 2022 5:15 am

You need to provide details. For any given input (don't know why you keep saying output, unless you are confusing pinout with output). I suggest you do the following for each AT input (AT1 - AT6) and AV Input (AV1-AV8):

-- what wiring is physically on your ECU connector? For AT3, is there wire in B16 (or pin 6 if an M880)?
-- For AT inputs, are any configured for digital inputs functions in Adjust->Digital Inputs Functions (these to not have to be setup in Adjust->SensorSetup->Input Setup)
-- What is currently configured using that Input in Adjust->SensorSetup->Input Setup?

Perhaps the available inputs will become clear.
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Re: Open pins for brake pressure and oil temp

Postby David Ferguson on Tue May 03, 2022 5:18 am

Do you have documentation on your wiring harness? You may find the unused input wiring goes to a spares / aux connector, or are sealed in an "expansion" leg of the harness.
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Re: Open pins for brake pressure and oil temp

Postby Stephen Dean on Tue May 03, 2022 10:20 am

Hi,

Another place to check is View | Raw Input Values... when connected to the ECU. An AT without load will sit around 4.99V and an AV should be below 0.03V without load. The Digitals should be around 4.7 ~ 5 V.
Stephen Dean
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Re: Open pins for brake pressure and oil temp

Postby Richard0990 on Thu May 05, 2022 7:29 am

Hi,

Thank you for your advice, I will check the volts when connected to see what isn’t wired presuming that is what you are saying that when they are unused they will be sitting at the voltages?

Unfortunately I do not have any documents but I am planning to make one when get the wiring correct, the pins are all wired apart from the second lambda pins. I will try your approach too to see if I can determine what is being used and if any are not, the whole loom is populated so I just need to spend some time going through wire by wire to see what is connected and what is not.

If I find a free pin would it be fair to say for a pressure sensor I would be looking for a ratiometric? And that I can tee into the 5v power and 0v ground pins on the ECU I’m sure the sensors all join into these power and ground pins anyway


Thank you
Richard0990
 
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