Generating a tach signal to drive stock tach?

[decipha]

holdout before you do, make sure its on pin 19

i don't recall doing the second part of the reassign so i may not have swapped it fully.

ill check when i get to my laptop

[decipha]

Here you go, give this a run and LMK. Should be all good.

Also reading back over the last page, your a/c probably puked the relief valve from being forced on by the clutch output being inverted. When you do hook it up make sure the a/c clutch engages when you turn the a/c on and disengages when you turn the a/c off and not the opposite.

Also i'm willing to bet the clicking you heard was probably the low speed fan output being reverted.

In any case this should be all good now.

enjoy

[Cougar281]

Yep, that worked as intended. Thank you! I'm guessing that'll make it into the XDF eventually?

I don't think the compressor puked due to being on when it shouldn't have been and over-pressuring the system because when it happened, it had been sitting without having been run for at least a few days, maybe a few weeks. It was just all of a sudden one day there was a puddle of compressor oil under it. But I could be wrong.

Yes, you're probably correct about it being the LSF relay.

Thank you for putting up with me lol.

Slight sidebar, I did notice a slight hum from the CCRM after the fuel pump shuts down. On key on, when the fuel pump is running its initial prime, there's nothing, but it starts right after the fuel pump turns off. I don't recall if it was there before or not, but it's exactly the same with the Mustang PCM, so it has zero to do with the different PCMs and quite likely has been there all the while and I just never noticed it. It's not the loud buzz that results when the fuel pump is set to returnless where the PCM is expecting feedback from a FPDM. And considering it doesn't seem present when the fuel pump is commanded on, it's probably not even something to worry about. Just figured I'd throw it out there to see if you have any thoughts one way or the other.

[decipha]

yep, just posted a new xdf

that hum may be the hego heater duty cycle

[Cougar281]

Thanks again for your help and putting up with me lol.

One thing I learned in this is that there are a lot of different hardware numbers that can be used, even if they're not technically designed for the application or running code.

I've never understood how it makes more financial sense to make 60 different PCMs for all kinds of applications that are not interchangeable (at least according to them), vs one that can handle everything from a v10 down to an I4 turbo, with the only difference being programming. That would also simplify the supply and repair chain. Imagine if a dealer only needed to stock one part number to take care of the entire vehicle line within a date range...

[decipha]

makes perfect sense

if they can save $10 on ecu components x 20 million vehicles == 200 million saved

[Cougar281]

I guess it depends on how you look at it... Is it money REALLY saved considering all of the development that needs to go into each one that's designed and released? I dunno... I don't have any info on what it costs to develop each one or build each one... It just seems to be that all things considered, it would make more sense to develop one all inclusive unit. This is a big problem in the Chrysler world... For example, trying to find that very specific ECM for a 2004 TJ 2.4L manual is like searching for hens teeth, and if you do find one, it's $$$$$$$$$$$$$$$ and will almost certainly fail in the same way (O2 sensor heater drivers). I suspect it's part of 'planned obsolescence', except at least here in the Ford EEC-V world, we have you to teach us that there are a lot more hardware numbers that can be used than the normal cross references would suggest. I would never have thought that I could run the same calibration from the Mustang PCM on the Marauder PCM if not for you. Oh, and if you want, you could probably add MPC-19D to your list (since it's not there) as that's the hardware ID of the PCM I'm running now.

[decipha]

Yeah definitely, they have people specifically for cutting cost when they can and saving money on unnecessary circuitry is a no brainer. Highly unlikely they paid the guy that went through and made the variations a fraction of the money they would have spent otherwise. Making a revision to a hardware class is pretty straight forward. I highly doubt they spent more than 5 or 10 minutes tops for each one. And within the same class it makes no difference they just order x amount of ecus with that circuitry. Thats exactly why the marauder and mustang ecu are the same hardware class but have different circuitry. They just ordered what they needed.

Hardware numbers are only part of the equation, its a bit involved to cross reference the hardware configuration code in them as many even in the same era are not compatible due to changing pin registers usually. I would never recommend for anyone to blatantly try out different ecu's as it can easily cause damage. Hanging an injector open can trash an engine in due time. I've seen some pin registers that would do just that when compared to similar ecu's that are a different class.

Also, to give more insight in to what exactly an ecu hardware class is:

The hardware class is specifically the hardware pin mapping configuration.

Two ecus are in the same class if they share the same or a compatible hardware pin mapping configuration. This doesn't mean that they have the same pin count or outputs, it means the pins are assigned to the same register locations and they can run the same software (tune/strategy) without corruption. (such as rzasa and fbgi0)

On the flip side, two ecus would not be in the same hardware class if a specific pin register is assigned to something incompatible. For example an injector pin if it were to cross compare and be assigned to the tcil that would be a problem. Thus those wouldn't be the same hardware class ecu.