# MS2 Extra Output problem



## tfatout (Feb 20, 2008)

I was hoping to get some help on this one I have done some searching and have been unable to track down an answer. I am trying to run a fan off of one of my spare outputs I have tried fidle, iac1 and 2 both a and b wires and have not been able to turn the fan on. I am wiring it through a relay but still have nothing. I have tried enabling all the extra outputs in tunerstudio with all possible options for trigger value and power on value. I built my board over a year ago and cannot remember if there was something I needed to do on the board to get these outputs working. Any help is greatly appreciated.


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## need_a_VR6 (May 19, 1999)

To use the IAC outputs you need S12(c) to JS9, and remember it's ground when active.


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## tfatout (Feb 20, 2008)

Awesome! Thank You I will give that a try this week.


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## tfatout (Feb 20, 2008)

Would this be a proper representation of how to correctly wire in the relay for my application?

http://www.ado13.com/techs/relay.htm


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## need_a_VR6 (May 19, 1999)

Sort of, 86 should just get hot or ign sw power, 85 will run to the MS pin that you're trying to control with. Which brings me to another question.. you have JS0 or JS2 jumpered to an external pin?


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## tfatout (Feb 20, 2008)

I do not have JS0 or JS2 jumpered to anything. Should I use one of these instead. I am planning on using the boost control mod from diy. Maybe I should save the iac outputs for that?


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## need_a_VR6 (May 19, 1999)

Well JS0 and JS2 ARE the IAC outputs for MS2, so yes they need to be jumpered to something to get them to work! I know they can drive a PWM valve but not sure about a boost solenoid (I would think so) make sure those features are supported in the code for those outputs.

Just FYI JS0/1 are a pair with inverted outputs, and JS2/3 are a pair with inverted outputs. Generally JS1/3 dont' get used for anything but stepper idle valves.


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## tfatout (Feb 20, 2008)

Yeah after reading some more last night in the mega manual, I understand exactly what you are saying, and I remember now when I built the thing a year ago why I chose at that time not to install the jumpers for the iac outputs. Thanks for your help Paul!


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## need_a_VR6 (May 19, 1999)

No prob and good luck!


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## tfatout (Feb 20, 2008)

Ok, So I am still having an issue with this. Here is what I have done. I have wired in jumpers from JS0 to IAC1 and JS2 to IAC2. Then I hooked up the relay as follows: 86 to Fused 12v Source Jumped 86 to 30. Pin 85 goes to IAC1A on the MS. and 87 to positive lead on the fan. 

My tunerstudio settings are as follows: IAC2 enabled Power on Value:0 Trigger Value:1
conditions coolant > 185 Hyst: 10
rpm > 450
When I turn the key on the fan comes on no matter what conditions I have set. Also when I enable IAC1 and disable 2 the fan does not turn on. 

So questions, Why is the control flipped from IAC1 to IAC2 and why aren't the conditions working properly?


Thanks again!


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## tfatout (Feb 20, 2008)

Soo... no ideas I take it?


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## ValveCoverGasket (Mar 20, 2002)

the mapping between the labels on the underside of the board (JS0 and JS2) doesnt line up very well with the dropdown list of available "outputs" when selecting them in MS2e... i struggle with this every time if i dont have the notes of which dropdown selection corresponds with which pin sitting in front of me

it sounds to me like you might have the outputs mixed up between the software and what youre actually using to drive your relay... unfortunately im not at the shop computer to tell you what i had written down for how the outputs line up


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## need_a_VR6 (May 19, 1999)

JS0 = IAC1 
JS2 = IAC2 

.. in the code/firware/tuning software. You say you have JS0 to IAC1 but is that IAC1A (25) or IAC1B(27) or IAC2A(29) or IAC2B(31) on the DB37 side.


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## tfatout (Feb 20, 2008)

Sorry for the delay, I am still having troubles with this. I have s12c jumpered to js9 and I have JS0 jumped to IAC1A and JS2 to IAC2A. I do not seem to be getting any output at either one of these wires. :banghead: Any thoughts? I am getting pretty frustrated with this lately.


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## ValveCoverGasket (Mar 20, 2002)

it is possible to ruin the extra output portion of the ms2 chip and have everything else (rpm in, ignition, etc) working fine...


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## tfatout (Feb 20, 2008)

Is there a particular test I could do to double check that? by using a voltmeter?


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## need_a_VR6 (May 19, 1999)

I'm sure you can damage the stepper driver chip by hooking it up to something that draws too much current. 

I suggest testing for voltage on that pin and configuring and output to change with something easy to vary like tps and set a threshold and see if it changes.


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## ValveCoverGasket (Mar 20, 2002)

need_a_VR6 said:


> I'm sure you can damage the stepper driver chip by hooking it up to something that draws too much current.
> 
> I suggest testing for voltage on that pin and configuring and output to change with something easy to vary like tps and set a threshold and see if it changes.


and if it doesnt change, and you reflash it (just for grins), and it still doesnt change... try another output port.
if no luck on either, then its fairly safe to say the chip is toast


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## tfatout (Feb 20, 2008)

I'll give it a shot! I will be crossing my fingers. I find it hard to believe I could have blown something on the outputs because I just yesterday installed the jumper from s12c to give power to the outputs and I was not getting anything different from before. Oh well, I will check it. If it does not work, I am just going to get a thermostatically controlled fan switch and call it good.


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## tfatout (Feb 20, 2008)

So finally it seems to be working correctly, I decided to use the fidle output to control the fan, and voila everything is working perfectly. Not sure if the other ports are blown, but I kind of doubt it. Either way one more thing down, were pretty close now. Thanks for everyones help on this!


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