keep in mind, your pcm may not be sending out what the CCM needs or wants, and may never "handshake" with the CCM until you have programed the ls1 PCM to send the right information. that information was the gigantic post above, with all the code....

 

That is was I was saying before but I guess I did not convey it very well.

 

I gotcha, I missunderstood. I thought you were hung up on the comm style, not the actual data.

The Helms says what the ccm needs and where it comes from. Compare this to what the ls1 pcm puts out on its serial line. (how you obtain that info is still a question to me... but something tells me this data can be read by a tech 2 or some other form of serial data reader... like tunercat, hptuners, winaldl, lt1edit, etc etc etc. A simple max232 or whatever homemade cable might work)

 

Im going to get it finished up and put the CCM thing on the back burner for now. Thanks for your help. OH and you asked if I knew computers...
My office:

 

Well hell! What do you need my help for!?
You look like you have the networking side covered.

Looks like you have all you need there. Actually, your going to need something that's probably older than any of that. Lol.

 

If I want to print and access educational programs then yes.
Two different worlds.. but similar. Again thanks for the edumacation.

 

MY IDEA HAS BEEN DONE IN THE PAST AND IT WORKS!!!

found from massive amounts of searching... a small amount of info all over the web. Guy made his own opti pickup wheel and amplified the voltage at the optispark for a 12v square wave instead of the optis 3v. It worked and was running his twin turbo lt1. Thats the last bit of info I found anywhere on this guy/car. This was in 2009.

ref: http://www.camaroz28.com/forums/comp...-493226/page8/

 

http://www.interfacebus.com/Automoti...J1850_Bus.html
comm protocol for gm j1850, theres more to that...

http://www.diy-efi.org/gmecm/ecm_info/obd2/
The mother load of info for interfacing to read and write obd2 GM data. this includes chips and comm data.

more info
http://www.andywhittaker.com/en-gb/ecu.aspx


All this info is what I plan to use to find out how to make the ls1 pcm talk to the c4 (94-96) ccm. If its possible.
Another avenue is looking into the involvment of swapping in the ls1 bcm... (and cluster, and... and... well why not just buy a c5?)

 

Lalalalala

Back to working on this. Changed jobs ( went from advanced component level electronics tech at the FAA, to now a remote submarine pilot/tech for a large oil company) and rebuilt my lt4 again. I am currently offshore with extremely limited Internet.

Where I am at now...
The 24x signal and 1x signal can be produced by the optispark. Without changing the reluctor. It's as simple as a frequency divider. Duh? Why didn't I think of this before? 360/15=24 (720/30=24)
The start and stop of the 1x signal can be made from the 8x signal on the opti using two if the 90* pulse marks.
I have contacted Delteq and LTCC, awaiting responses on how they convert opti signal. If I can make a simple circuit to divide the high res and produce the low res, then that's in the bag. Cheap, easy, effective.


So no reason to physically take off or touch the optispark.

I still think either the pim or the piggyback method is going to work for the UART data to the CCM.

Anyone else have any more light to shed?

 

So what your saying is for the dash and CCM to work you have to keep the Opti-Spark? But the engine runs on the LS1 setup?

What is the point then? Engine might run but nothing else works right. Unless, I'm mistaken.

 

You are mistaken.

For the dash to work the language for the CCM must be made properly. It has nothing to do with the optispark.

The objective, design a system to be plug and play to use the better ls1 PCM.

To do this I wish to NOT remove the optispark. Or even touch it. I simply wish to use its internals to produce the signal that the ls1 PCM requires.

This will use the same ignition setup that is on the LSX cars, only the triggering comes from the opti. The optical side of the opti is extremely robust, as proved by Nissan. (Nissan uses the same design and exact same sensors. They don't have anywhere near the amount of failures cause they're ignition cap is far from optical pickups and they didn't put a water pump above the distributor!)

The point: USE A BETTER PCM

One that can be tuned by virtually every tuner out there.
One that can run lumpy cams with ease
One that makes turbos and supercharges a reality
One that makes nitrous easier
One that has the possibility for launch control
One that can emulate live
One that can interface with an iPhone
One that is light years beyond what we have now.

Aside from a few mechanical advantages, the LSX engines make all their power from better ignition, fuel and spark control.

 

I hear ya on the LS1 ECM advantages.

As long as you can get the Stock CCM, Dash, ASR/ABS, etc...to work with converted LS1 data, that is all good.

I agree with the Optical Sensor with Nissan's use of it. However, they have it in a better location. The GM one, even in your application, is still subject to a lot of heat, moisture (water pump failure). Thus potential failure. Now taking away the high voltage is a good step. The LTCC system does this.

Since your point is using the LS1 PCM, I guess that is the point.

For me personally, I like the idea of doing a rear mount in the traditional SBC way of a Opti-spark distributor that plugs into the stock harness already there only its mounted in the back. Then run the LTCC setup off that. Retain stock ECM and No other tuning/wiring issues. CCM, Dash,etc...Should be 100% reliable compared to the front mounted unit. Easier to do, but you would not have the LS1 capabilities.

All very interesting, keep us posted.

The 24x Conversion would be easy if building a race car, just rip the stock gauges out and ccm and put in a custom setup. The ABS/ASR needs a compatible tach feed but that should not be too hard. You'd need the Speedo to be compatible with the VSS. Everything else is basically a non-issue in a race car.

Like I said, intresting.

 

Yeah, if everything works it will be golden. I am fairly certain it can be done. I am working on it.

I agree to an extent. Below the water pump is a less than ideal place. I have personally been victim to one of these failures on my second C4. In light of this, I have thought about rerouting the weep holes path... until I tried the water test on an optispark I had removed. I plugged the vacuum lines and hosed it down. No water got in. I am satisfied the newer style opti housing is water pump failure proof.
I have been in correspondence with LTCC, as I am interested in how they have done things. I wonder if anyone has a report of a failure with the LTCC system on the opti side of the house???

I see and understand your preference. The issue I have is tuning. I cannot find a local tuner. I have seen the one available system for the LT4 and I do not want to pay for that when I see a possible avenue that will take more mental work, but cost less money. Ive done things like this in the past, and the work is documented on other forums. I successfully converted to DIS from a distributor, Re-pinned and rewired engine harnesses, and upgraded ECMs to newer ecms, and swapped newer engines into older platforms. This particular case has a few little hurtles that are of technology I am immersed in daily.

Yeah, if I had a race car, I wouldnt fathom this idea. But I am like other owners who love the C4 but want the newer technology and capability.



No update on the design of things today. Correspondence with LTCC and research is underway.

 

Yeah, de-pinning, splicing wires, spending time in the FSM to make it work, does not scare me at all.

Like you said, the issue is communication language between the newer LS1 PCM and the older stuff.

Sounds like a really neat and interesting project.

The idea of running a stock functioning car with all its bells and whistles while having the ability to tune/modify, and reliability of LS1 ECM control of the LT1 is just .

 

What I am finding is that the language is not a barrier... its simply making the ls1 (for all intensive purposes, we will call this the 0411 pcm) speak UART. Which, by thumbing around, it does speak UART. It also speaks Class II.

What GM did on the GTO was build a translator. It is called a PIM (powertrain interface module).
What it did was take the Class II language from the PCM and used it for Theft control. It also dispatched some of the Class II data, by turning it into UART. It also received UART from the cluster, starter, and key (maybe more) and sent it back to the PCM to allow the injectors and starter enable. This all talked to the BCM, which was head hauncho of the convo.
So to put it all together, we find that to use the PIM as it was designed, we would have to make sure that it is synced with the BCM and with the PCM. This agreement between devices is critical, as the engine wont run with out this information from all partners. Scratch this idea off the list.

The next avenue is to verify that infact the 0411 is capable and does speak UART. If it does, what does it say? Does it say the things we need it to say, in the correct order? If it doesnt, can we change it?
The data that is spit out of the LTX PCM can and has been recorded. We can get this information. With this information, and with the knowledge needed to dig into the 0411, we can take this program and write it onto the 0411 UART section of the chip. When the 0411 starts up, it will start running the UART from the LTX PCM. And if it is exactly like the LTX PCM data, it will work exactly like the LTX PCM. No need for a translator, as the UART language is the same no matter what device it comes from. UART stands for Universal Asynchronous Receive Transmit. It is literally universal, as it is used on virtually everything I have ever worked with in the electronics world. Setting the baud rate should be easy, as it looks like it may be a function of the clock speed of the UART chip. It probably is already at 8192 baud. The voltage level should be the same as all UART is, 0v= low 5v=high. It looks like its only 8 bit words from the LTX PCM, so the 0411 should be able to do all of this.

So tonight I will research how to program microcontrollers. Then see if I can find out what information comes from the 0411 pcm and make certain its UART can be used.
I am considering buying a Tech 2 to aid in the download of the data. And something tells me that the 0411 will need some relearn or vin input...

 

What I am finding is that the language is not a barrier... its simply making the ls1 (for all intensive purposes, we will call this the 0411 pcm) speak UART. Which, by thumbing around, it does speak UART. It also speaks Class II.

What GM did on the GTO was build a translator. It is called a PIM (powertrain interface module).
What it did was take the Class II language from the PCM and used it for Theft control. It also dispatched some of the Class II data, by turning it into UART. It also received UART from the cluster, starter, and key (maybe more) and sent it back to the PCM to allow the injectors and starter enable. This all talked to the BCM, which was head hauncho of the convo.
So to put it all together, we find that to use the PIM as it was designed, we would have to make sure that it is synced with the BCM and with the PCM. This agreement between devices is critical, as the engine wont run with out this information from all partners. Scratch this idea off the list.

The next avenue is to verify that infact the 0411 is capable and does speak UART. If it does, what does it say? Does it say the things we need it to say, in the correct order? If it doesnt, can we change it?
The data that is spit out of the LTX PCM can and has been recorded. We can get this information. With this information, and with the knowledge needed to dig into the 0411, we can take this program and write it onto the 0411 UART section of the chip. When the 0411 starts up, it will start running the UART from the LTX PCM. And if it is exactly like the LTX PCM data, it will work exactly like the LTX PCM. No need for a translator, as the UART language is the same no matter what device it comes from. UART stands for Universal Asynchronous Receive Transmit. It is literally universal, as it is used on virtually everything I have ever worked with in the electronics world. Setting the baud rate should be easy, as it looks like it may be a function of the clock speed of the UART chip. It probably is already at 8192 baud. The voltage level should be the same as all UART is, 0v= low 5v=high. It looks like its only 8 bit words from the LTX PCM, so the 0411 should be able to do all of this.

So tonight I will research how to program microcontrollers. Then see if I can find out what information comes from the 0411 pcm and make certain its UART can be used.
I am considering buying a Tech 2 to aid in the download of the data. And something tells me that the 0411 will need some relearn or vin input...

 

Staying posted on this.

 

Good to have you on board!

I may need some entrepreneur business coaching soon

 

Just to clarify, are you attempting to use an LSx PCM but implement the Opti as a sequencer? Obviously you know about EFIConnection and their CNP conversion. Not inexpensive but those guys did a lot of work on developing that. However, LSx conversion has always been a bit of an issue for Corvette due to the ECM/CCM handshaking which you appear to be addressing. My interest stems from the LT5 ECM and the DIS waste spark.
The LT5 ICM is different from other GM modules and the reluctor wheel on the LT5 (cast as part of the crank) uses 9 notches. Its in the middle of the crank for the greatest possible stability, a necessity at
7000+rpm. All of which makes CnP conversion difficult. so I am lurking to see what you come up with.

 

Yes, The overall goal is to use the 0411 PCM. Objectives are to use existing means to generate crank trigger pulses, have fully functioning peripherals, and an ease of installation.

Yup, they did a bunch of work, that requires the end user to do a bunch of work. I know you have a zr1, but if you have ever had to yank off an opti, its no fun chore. To add insult to injury, they require the user to remove the timing cover... AND pay a chunk of change. I think differently than most, and the way I look at their method is "you want me to pay $2000 for something that doesnt work on my car, and you want me to spend 8-16 hours installing it?" You would almost have to pay me to get me to remove the crank hub on a LTX C4 with the engine in the car.
When I see what they have done, I think "I can do it better, for cheaper, and make everything work"

The LT5 has a unique designed system. But, I have designed a coil on plug system that would work just fine for the stock LT5 ICM. In fact its nothing more than removing the existing coils, using spade connectors and wiring in the individual coils from say a Chrysler 3.5l. The ICM does all the work already, and you just "distribute" the signals to individual coils. Working examples are on my brothers 3800 SC3 Fiero and a buddies 500hp Eagle Talon.
Yet I see you want the whole functionality of a new PCM, much like myself. A separate idea would have to be designed for the crank trigger on an LT5. Regardless, the position of the crank trigger is not critical to RPM, as many crank trigger fired engines easily exceed 7000rpm and the triggers have been located everywhere you can imagine. One particular example is a unit I made for a 7x reluctor on a GM 3500 v6, the reluctor was on the crankshaft snout. It was infront of the balancer, and not pressed on, only guided and bolted, like a washer. I spun to 7200 rpm with no errors.
The way these crank triggers work is with a hall effect sensor. They detect a change in magnetic field as it passes in front of the sensor. It is a transistor inside of the sensor. When the opposite pole from the transistors make (PNP or NPN) it forward biases the transistor allowing the voltage to flow through. The end result is a pattern that is cut into the metal reluctor. As each notch, grove or tooth passes, the status of the transistor changes, and you get a square wave dc signal.
The sensitivity of the sensor is not all that great, meaning the sensor needs to be pretty close to the moving metal to detect the change in magnetic field. I dont remember exactly but I think it was something like .20" is the maximum gap between the reluctor and sensor. Regardless of the distance to the reluctor, there is no requirement for position in the engine. To add, if you have a deflection of .20" on any part of the crank, you would have a grenade with a pulled pin.
The "noise" that gm refers to on their LSx is magnetic noise, or EMI. Since this sensor uses magnetic fields to detect the reluctor, any interference can be caused by another moving chunk of metal. This is the reason the reluctor is on the center of the cranks on some GM vehicles. It was the most neutral spot on the crank to cast in a gigantic chunk of metal and it saved cost, as this was done during crank casting. (probably not a cost concern on the LT5) Had GM decided to use a thin metal plate (like they did later on) they would have not chose to cast a gigantic weight into the middle of any part in the rotating assembly, like they did later on. The location of the reluctor in the center of the crank was for cost, ease of location, and partially misunderstanding/desgin requirements. (by misunderstanding or design requirements, I mean that there is no reason for the reluctor to be as wide or as stout as it was on the LT5, 60* V6, or Iron Duke, meaning they either didnt know that the sensor cant see very "wide" and there was no need to have something that large, or they had to make it that big due to casting in the middle of a crank)
Having said all of this, I respectfully argue the point of stability for the reluctor location on the LT5.



As an update to development, I have gotten some headway on the pinout conversion. I am making an excel program to match the pins from the old to the new, aligning them by circuit series, function of the circuit and wire color. The end result will be an excel spreadsheet that will show what wire needs to go where, what needs to be added, and what would happen if that wire was not connected.
As it stands, I think there is a way to simply make an adapter to plug the old harness into the new PCM, route a few new wires, and call it a day. No need to repin 160 wires, that stuff is for the birds.

Also, I have found that there is the possibility of using the newer style electronic cruise control modules. Updates coming soon.

-Jonathan