LS1b (411) PCM Swap

[VetteVet]

I brought up the possibility of a 411 PCM swap in Jerry's "Ignition Impulse @ Balancer/Dampner" thread because it was somewhat relevant to the thread topic, but at this point I'd like to take the liberty to break it out into a new thread.

As has been discussed, there are several potential "show-stoppers" involved. The most serious ones are listed below:

1. Secondary system issues
2. 24x CKP and 1x CMP signals
3. CCM communication

Here are my proposals as to how these obstacles can be overcome:

1. In my opinion, this is by far the trickiest of the bunch. The 411 PCM software, as it is currently written, cannot handle our secondary injectors, nor the rest of the secondary hardware. This is, however, merely a software and not a hardware problem. Remember, our ECMs were not designed to handle dual mode operation either, but GM kludged together a solution by adding extra spark and fuel tables, solid state secondary injector relays, a secondary actuation solenoid, vacuum pump, differential vacuum sensor, the necessary code modifications, etc. Their are 2 possible routes to take toward resolution of this issue:

a.The easiest solution would be a one tailored toward engines that have had their secondaries removed. The 411 code would need to be modified so that it operates as designed at idle, but at off-idle it energizes unused outputs to bring the secondary injectors online while at the same time scales the pulse width by a factor of 0.5 (or 0.51 if we go by the ZR-1 ECM calibrations). I don't believe that we would need to implement separate fuel and spark tables as the engine would be operating on "primaries only" in such a narrow window and not at heavy load.

b. The preferred solution would be to implement full secondary system functionality. This would require more extensive code modifications, but the 411 PCM definitely has the necessary hardware and processing power.

2. The signals required to operate the 411 PCM are 24x CKP (24 pulses per crank shaft revolution or 48 pulses per camshaft revolution) and 1x CMP (1 pulse per camshaft revolution or 1/2 pulse per crankshaft revolution). Our CKP signal is 8 (or 9 if you count the odd synch pulse) VR (AC) pulses per revolution. This signal is processed by the Ignition Control Module (ICM) and the ICM generates a signal of 4 pulses per crankshaft revolution on the REF HI circuit, which is fed to the ECM. Installation of a 24x reluctor wheel combined with an L21 Hall Effect CKP sensor can provide the 24x signal to the 411 PCM. While our CMP signal is also 1x, it is not a 50% duty cycle, so a reluctor wheel with a 50% duty cycle (high for 180 degrees of camshaft rotation and low for the other 50%) combined with an appropriate Hall Effect sensor can provide the CMP signal. Assuming suitable mounting locations can be found, the appropriate reluctors can be fabricated and everything can be installed with the proper phasing, these signals should be suitable for running the engine.

3. Regarding communication with the CCM, I initially thought that this was going to require fabrication of an interface. The Gen III PCMs communicate via the Class II protocol and the ECM, CCM and other modules in our cars communicate via 8192 baud UART. The CCM acts as the master device in this arrangement and is the only device that the ECM communicates with directly. After lots of research, I recently found out that GM (Pontiac GTO) and Holden have produced cars with Gen III PCMs coupled with vehicle systems that utilized 8192 baud. They have a plug and play module called a Powertrain Interface Module (PIM) which translates between the PCM Class II and CCM (or BCM in later vehicles) 8192 baud protocols. While some code mods may be required so that the PCM can understand the CCM messages and respond aprropriately (speak the same dialect), the PIM will allow them to communicate at the hardware level (speak the same language).


Sorry for the long post, but I wanted to get my major ideas out on the table up front.

At this point, I'll open up the thread to comments (critical or not), questions, ideas and suggestions.

Thanks,
Jep

[RHanselman]

Jep,

I've looked into using the LSx type PCM in an effort to solve some issues with my turbo car. I was specifically looking into the Big Stuff 3 system which has an option for 16 injectors. I would think this would solve most my issues especially if I could get it to talk with the CCM. This PIM sounds like it may be the answer...

Cheers,
RH

[VetteVet]

Ron,

If you were looking into the 411 PCMs then I'm sure you're aware that EFILive anf HPTuners offer 2 and 3 bar custom operating systems. I haven't looked into them enough to know if they support wastegate control, but do know that even the stock code has a table for mapping out fuel pressure so any type of FMU or VFPR can be accomodated very easily to take care of the increased fuel demand.

Jep

[RHanselman]

Jep,

411's were not in my crosscheck when I was doing the initial research. Do you have a website you like best?

[VetteVet]

Ron,

You can go to the EFILive and HPTuners websites:

http://www.efilive.com/
http://www.hptuners.com/

Both sites have user forums and offer custom operating systems that support boosted applications. I'm sure if you poke around on the forums, you should get a feel for the capabilities.

Also, both sites offer free demo versions of their software for download. I have installed both and they have been invaluable for getting a feel of the 411's capabilities. GM really made quantum leap advances over our ECMs.

The whole code segment thing took a while to get my head wrapped around. For example, if the binary file for a 2001 Corvette is closest to meeting my needs, but the transmission that I want to use was never offered in the Corvette, then all I have to do is swap the transmission segment from another vehicle into the Corvette binary and the PCM can now control that transmission and all of the tuning parameters that apply to that transmission are now valid.

You can also look at these forums as well:

http://www.ls1tech.com/forums/
http://www.ls1.com/


There are many others, but these should get you started.

In other news, I have brainstormed the crank and cam position signal issue and think that I have a bolt-on solution. More news to follow as I get the details worked out.

I have a PCM and PIM on the way. $59.00 for the PCM and $99.00 for the PIM. I can't believe how cheap these PCMs are.

I had a good conversation today with Jon at F.I.C. I think the injector situation can be handled. I've got several ideas and am not sure which, if any, will end up being the final solution.

Once I have the PIM and PCM in hand and my test bench is finished, I'm going to try to see if the PCM can be made to talk to my CCM. By the way, most of the dash functionality is not tied to the CCM. All gauges should work fine even if the PCM can't talk to the CCM. I think the only things that wouldn't work would be the fuel economy stuff and the engine diagnostic display via the LCD (don't quote me on this because I haven't looked into this extensively yet). If we can get the PCM and CCM talking via the PIM, then everything should work normally. The PCM has two independently scalable outputs for speed signal, so it will accomodate the signals needed by the speedo and cruise control.

Thats it for now. If you think of anything else, feel free to post in this thread or PM me. You can also contact me via the methods below.

Thanks,
Jep

vettevet(at)charter(dot)net
Cell: 985-789-5118

[-=Jeff=-]

Anything on the LCD is controlled by the CCM.. just a FYI

[VetteVet]

I got my LS1 crankshaft reluctor today. $30.00 for a brand new part!!

http://i827.photobucket.com/albums/zz195/vettevet/IMG-20120302-00004.jpg



Note the 24x pattern that the LS1 uses:

http://i827.photobucket.com/albums/zz195/vettevet/IMG-20120302-00005.jpg



Coincidentally, it is the same O.D. as the LT5 harmonic balancer pulley.

http://i827.photobucket.com/albums/zz195/vettevet/IMG-20120302-00006.jpg

[RHanselman]

How are you going to mount it? Also, would you need to run 16 injectors or could you use 8 large in the primary location and just keep the secondary inj's in as inactive hole plugs?

[VetteVet]

Ron,

I don't plan on using that wheel. I purchased it to get the measurements to design a one piece solution that would attach to the balancer.

I'm about 50% done with the CAD design for the CKP reluctor wheel assembly. I still need to design the sensor mount.

I've been concentrating on the CMP sensor housing design, as that is the more challenging one. I'm about 95% done with that.

As far as injectors, I've made phone calls to some gurus and am pretty confident that it can be run on 16 injectors full time. I'm still working out the details on that. More information to follow.

Within the next week or so, I should have some 3D CAD images to post up.

Jep

[RHanselman]

What do you think of the wheel that Jerry has?

[VetteVet]

Ron,

I don't know what Jerry has. It was probably for some type of Engine Management System retrofit and it does have 24 slots, but it won't be able to produce the signal that the LS1 PCM would need. See below:



http://i827.photobucket.com/albums/zz195/vettevet/99LS1CrankSignal.jpg

The complete document from which this was taken can be downloaded here:

http://www.bowlingss.com/DownLoads/Parts%20Manuals/Holden_LS1.pdf


Jep

[RHanselman]

Got it...

[Merlot566jka]

Following this, and have borrowed some of your material. And have some to contribute. http://forums.*************.com/c4-tech-performance/3029224-24x-conversion.html#post1581004077

I don't know if this is any contribution, but seeing as we both are working to use the same PCM on the same car, maybe we can help eachother.

[RHanselman]

Jep,

Any updates?

Cheers,
Ron

[Merlot566jka]

Hey guys, how does the lt5 get its crank trigger pulse for the icm?

If its a pressed on disc around the crank, look at GMs 3400,3500 v6 engines. They have a large inner diameter wheel with the 24x wheel pressed onto the center of the crank. This is in the same place as the old 2.8/3.1 crank reluctor wheel. The significance is that the old cranks had the grooves for the reluctor machined into the crank, but the newer wheel can be pressed on over these old machined marks.

Now take this info and use it as you will, but I have a good feeling that GM kept things universal in some aspects. I would bet that if the lt5 has a machine 9x reluctor or a pressed on reluctor on the crank, that the outside diameter of this part onthe crank is around 5.75". Anyone know if this is true?

[Tyler Townsley]

Hey guys, how does the lt5 get its crank trigger pulse for the icm?


The LT 5 is not a GM derived design is is a LOTUS design with very little copied from existing GM ignition designs.
The timing notiches are cast into the crank and picked up from a sensor.
Here is an explaination from the service manual.

http://deliquescence.net/~tyler/prototype1/page09.jpg
http://deliquescence.net/~tyler/prototype1/page11.jpg
http://deliquescence.net/~tyler/prototype1/page12.jpg
http://deliquescence.net/~tyler/prototype1/page13.jpg
http://deliquescence.net/~tyler/prototype1/page14.jpg
http://deliquescence.net/~tyler/prototype1/page15.jpg
http://deliquescence.net/~tyler/prototype1/page16.jpg
http://deliquescence.net/~tyler/prototype1/page17.jpg
http://deliquescence.net/~tyler/prototype1/page18.jpg
http://deliquescence.net/~tyler/prototype1/page19.jpg
http://deliquescence.net/~tyler/prototype1/page20.jpg
http://deliquescence.net/~tyler/prototype1/page21a.jpg
http://deliquescence.net/~tyler/prototype1/page22.jpg
http://deliquescence.net/~tyler/prototype1/page22.jpg
http://deliquescence.net/~tyler/prototype1/page23.jpg
http://deliquescence.net/~tyler/prototype1/page24.jpg
http://deliquescence.net/~tyler/prototype1/page25b.jpg
http://deliquescence.net/~tyler/prototype1/page26.jpg
http://deliquescence.net/~tyler/prototype1/page27a.jpg
http://deliquescence.net/~tyler/prototype1/page28.jpg
http://deliquescence.net/~tyler/prototype1/page29b.jpg
http://deliquescence.net/~tyler/prototype1/page30.jpg

Tyler

[Merlot566jka]

Right, the LT5 was a fresh design. I suppose the point I was getting at was the crank reluctor wheel is inthe middle of the crank, like I had thought. This design was used on many other GM vehicles during that era. While the lt5 ignition system wasn't used on any other GM v8, it was a similar design to what they had existing in other DIS systems. I knew lotus designed the engine, merc manufactured the engines, but I have a good feeling GM had a hand in the ignition, fuel and ECM. But I am in no way an expert on the LT5, I know very little about this amazing machine.

On the GM designs that were similar, they had a reluctor cast into the crank, and the grooves were machined. The v6s used 7 notches, similar to how the LT5 used 9, one for the reset. The used an ICM that controlled much if not all of the spark control using the signal that was returned from the ECM. I would Almsot bet they have the same connectors on the LT5 ICM with the same in and outs that the other GM DIS systems had.

Not to dispute the information you have provided, but this design is extremely similar to other GM designs of the time.

Regardless, the information I was providing is that GM made a 24x reluctor wheel, than can be heated an pressed over the existing crank on an older 60* V6. If, by chance, the cast reluctor inside of the LT5 is about 5.75 inches, this reluctor that was used on the V6 could be used on the LT5 for 24x conversion. I have one of these reluctor wheels that I am working with, and just thought I'd share that with you guys, just in case someone wants to give it some more research.

[XfireZ51]

Merlot,

The LT-5 ICM is unique to this motor. It uses a very similar 14 pin connector however it is quite a bit different from other ICM. Viewing the circuitry, you can think of the DIS as a co-ECM. The base of the LT-5 ECM is the L98. Remember, the L98 ran w 1 coil and a distributor. So something else had to be developed for multiple waste spark coil setups. Buick has their own for the GN but that's a six and the ECM dealt w issues like dwell from the start. The secondary injectors are driven by a secondary injector power circuit controlled by the ECM grounding the power relay. Firing of the secondary is strapped to the primary injector rather than ECM having a separate driver circuit for them. My point is that some
things may look the same but not necessarily analogous.
As for the slip on reluctor wheel, sounds like an expensive and cumbersome solution for using a CnP setup IMO. How about on the balancer?

[Merlot566jka]

EFI connections tried the 24x reluctor wheel on a dampner and they had too much noise on the hall effect for it to work properly. But I have used a 7x that I made and it was bolted on the outside of the dampner. I didnt have any noise issues, but that's a fairly low resolution compared to the 24x.
GM says they placed the reluctor on the LSx engines towards the back of the block because this is the "quiet" zone. If GM went through this kind of trouble, I imagine there was a good reason.

But at the same time, EFI connections 24x and 58x kits for the LT1/4 engines use the reluctor behind the timing cover. Their system seems to work, even if it's in the "noises" zone.


Thanks guys for all the info on the LT5 ignition. It's always good to see how it was done differently.

[XfireZ51]

Is there any doubt as to why the LT-5 reluctor is in the middle of the crank?!
7-8k rpm and that's the most stable spot on the motor. Someone else here would know more, but Marine did have an LT-5 w CnP.
Who would know about that?

[LGAFF]

Its the Bentley test engine, 2 were built....its in the video Thunder at Stillwater and its actually the motor that was for sale in MI a few years ago.

[XfireZ51]

Its the Bentley test engine, 2 were built....its in the video Thunder at Stillwater and its actually the motor that was for sale in MI a few years ago.

Lee,

Any of your MM contacts know any details?
What about Graham Behan at LPE?

[Hog]

There is another GM application which uses the 24x CKP signal and the 1x CMP(cam) signal. Its the 1998-2001 rpo L21 Vortec 454 which was used in MD/HD trucks as a replacement for the truck 366/427 engines. The L21 is the 1st BBC to run CNP(coil near plug-8 coils) and ETC(electronic throttle control). Basically its a L29 Vortec 454 (used in all 3/4 ton and 1 ton GM trucks from 96-00) with CNP and ETC. After MY2000 GM switched to the L18 8.1(496) GEN VII(GEN 7) BBC.

This crank reluctor wheel is the same wheel design that EFIConnection uses except it now fits the SBC crank snout.

Here are the GM P/N', this reluctor must be used with this CKP sensor.
Reluctor - 12552480 $19.10
crank sensor - 10456248 $71.77 as per GM parts direct

This reluctor wheel is much smaller than the LS1 wheels as its placed behind the balancer underneath a front timing chain cover.

The L21 used PCM's 16232148 and 16238212 which are the 1997-00 dual 80 pin connectored 512kb PCM's, the 411 PCM came after for the 01-02 Vette/Camaro/Firebird and a few 03 Vette applications.

Not sure if this might help or not, but its another (cheap) source of a 24x signal.

Page 11 of this http://www.allworldautomotive.com/featured/sites/enginepartsplus/images/EPP_CATALOG_Color_2011.pdflink has a pic. listed for a 1999-2000 BBC. On page 10 it shows the conventional Vortec 96-2000 Vortec 305/350 4x reluctor and the 1996-2000 Vortec V6 3x reluctor wheels. LS1(24x) and 8.1(24x) wheels are also listed with pics.


peace
Hog

[VetteVet]

There is another GM application which uses the 24x CKP signal and the 1x CMP(cam) signal. Its the 1998-2001 rpo L21 Vortec 454 which was used in MD/HD trucks as a replacement for the truck 366/427 engines. The L21 is the 1st BBC to run CNP(coil near plug-8 coils) and ETC(electronic throttle control). Basically its a L29 Vortec 454 (used in all 3/4 ton and 1 ton GM trucks from 96-00) with CNP and ETC. After MY2000 GM switched to the L18 8.1(496) GEN VII(GEN 7) BBC.

This crank reluctor wheel is the same wheel design that EFIConnection uses except it now fits the SBC crank snout.

Here are the GM P/N', this reluctor must be used with this CKP sensor.
Reluctor - 12552480 $19.10
crank sensor - 10456248 $71.77 as per GM parts direct

This reluctor wheel is much smaller than the LS1 wheels as its placed behind the balancer underneath a front timing chain cover.

The L21 used PCM's 16232148 and 16238212 which are the 1997-00 dual 80 pin connectored 512kb PCM's, the 411 PCM came after for the 01-02 Vette/Camaro/Firebird and a few 03 Vette applications.

Not sure if this might help or not, but its another (cheap) source of a 24x signal.

Page 11 of this http://www.allworldautomotive.com/featured/sites/enginepartsplus/images/EPP_CATALOG_Color_2011.pdflink has a pic. listed for a 1999-2000 BBC. On page 10 it shows the conventional Vortec 96-2000 Vortec 305/350 4x reluctor and the 1996-2000 Vortec V6 3x reluctor wheels. LS1(24x) and 8.1(24x) wheels are also listed with pics.


peace
Hog

Hog,

Thanks for the info. I haven't abandoned this project, but the flood damage to (and total loss of) my ZR-1 set me back. I have my replacement ZR-1 and all of my time has been spent swapping parts and getting it in shape. Hopefully I will be able to get back on this soon.

Jep

[Merlot566jka]

Jep,

I am still actively working on this, over here... http://forums.corvetteforum.com/c4-tech-performance/3029224-24x-conversion.html#post1582765003

Is the LT5 crank keyed on the nose?

-Jonathan

[VetteVet]

Jonathan,

Yes, the LT5 crank is keyed. I looked at your info on the other forum. It looks like you have dug up quite a bit of info that I had not found. On the issue of the PCM having native UART comms, are you looking at an LS1a PCM? I don't think that the LS1b PCMs have the UART output. My hope was to use an LS1b, as they are MUCH more capable units.

Jep

[Merlot566jka]

Jep,

How are you defining the difference between LS1a and LS1b?

From what I have found, They all used UART to connect with the Serial Data link. Either way, I am 99% sure that up until GM-LAN came out, the PCMs all had UART capability.

The point where it changed is when they went away from the 6800 series processor.

quote from Team ZR-1 Forum....

Ten years after vendors invented flash memory it arrived in the all-new, on-board diagnostic (OBD-I) 1994 LT1 Y/F-body powertrain control module (PCM).*
The spiffy new controller featured 128 kilobytes of flash memory and two 16-bit Motorola 6800 series processors. It actually used two separate computer boards, each with its own processor and flash memory, which many thought were independent for engine and transmission control, but GM referred to them as the Event and Time processors.*

The controller would remain unchanged through 1995 and was recognized with the*service code 16188051.*
The '94-'95 LT1 Corvettes used essentially the same PCM, but with one additional microchip to begin OBD-II-like communications. The Vette controller used*service code 16181333.

In 1996, the mandated arrival of second-generation on-board diagnostics (OBD-II) was the notable news. The LT1 PCM for '96 was similar in architecture to its predecessor, but featured a faster 6800 series processor and a doubling of one memory chip's size-for a total combined flash memory of 192 kilobytes.*

The service code for '96 was*16214399. The 1997 module was practically a carryover and is interchangeable with 1996 modules, but it hailed under a new service code of*16242921.*

The 1996 LT4 Corvettes also featured a relaxed knock module, which enabled more aggressive spark advance.*
Thanks to its plug-and-play interchange-ability, this removable knock module, identified by GM Part Number*16214681, became a transplant favorite for LT1-based '96 and '97 cars. Besides the knock module difference, the difference between LT1 and LT4 controllers was limited to the calibration.

Also making a splash in 1997 was the Corvette's all-new Gen III LS1 engine. A completely new PCM was developed to control the new engine architecture. The '97 LS1 module was designed around a much faster Motorola 68000 series processor.*
The unit's memory was also cranked up, now with a whopping 512 kilobytes on board. The pumped-up processor and memory allowed for a single integrated computer board, responsible for both time and event related computation.*

The module remained identical for 1998 as well, and had a service code of*16238212.*
A clean sheet approach to engine control was applied for the LS1 as well. The General still used familiar algorithms, such as short and long term fuel trims, but the mapping took on new looks and the interaction became more sophisticated, capitalizing on the addition of a crank position sensor and coil-on-plug ignition. However, the LT1 individual cylinder fuel trims were gone.

In 1999, the LS1 PCM was re-designed again. The connectors look practically the same as those on '97-'98 PCMs, but the smaller body of the new '99 PCM made it clearly distinguish-able.*

Even though the connectors ap-pear the same, the PCMs are not inter-changeable and the pin-outs are vastly different. Just plug-ging a '99 PCM into an older harness can damage the PCM due to the wiring differences.*
Internally, the redesigned LS1 controller featured tighter packaged electronics, but still utilized the Motorola 68000 chip, albeit with a faster clock speed. The '99 PCM carried over unchanged for 2000, and the two share a service code of*09354896.*

From a operating standpoint, the big news for '99 was the extension of the MAF table range. The '99 peaked at 12,000 Hz, up from the '98 peak of 11,250 Hz, which was easily exceeded. The increase in recognized flow potential carried out in load tables as well, expanding the peak from 1.0 gram/cylinder in '98 to 1.2 gram/cylinder in '99.*
The extra range enabled tuning for big engines. The faster processor made chugging through the maps at high rates (aka high rpm) more efficient as well.

In 2001, the LS1 PCM was upgraded again with a faster version of the Motorola 68000 chip. Additionally, some of the internal memory was moved around, making re-flashed, retro-fit interchangeability with '99-'00 questionable. Externally, the PCM is indistinguishable from '99-'00 modules.*

The '01 architecture remained unchanged across platforms through 2002, and again for 2003 Vettes. The PCM used service code*12200411. From an operating standpoint, this PCM introduced various algorithm improvements and mapping expansions, such as the advanced spark control tables-i.e., modifiers based on ECT, IAT, and AFR.

For 2003, the Gen III PCM for trucks was upgraded with an even faster version of the Motorola 68000 chip. The same upgrade was rolled out on the car side in 2004 Vette and GTO.*

The flash memory was now doubled from 512 kilobytes to 1024 kilobytes, to help facilitate further expansion of control coding. Externally, the new PCM was identifiable by its 'green' connector (replacing the 'red' connector found on '99-'02 PCMs).*
This PCM would remain basically unchanged through its remaining usage up to 2007.*
However, several service codes existed due to internal manufacturing or sourcing changes, such as Intel-brand flash memory or AMD-brand flash memory.*
This brand-swapping was fairly transparent to the user, but caused tuning and diagnostic tools to be re-designed to ensure compatibility. The service codes for '03-'07 include*12576106, 12586243, 12586242, 12583560, 12583561, and 12589463.*

These PCMs are interchangeable, with a complete re-flash of the appropriate operating system. Thanks to its fast processor and large memory, this PCM is considered the optimal choice for LS1 transplants.

By 2008, federal law requires all factory controllers to be controller area network (CAN) based. GM got a jump on the new architecture with the Gen IV LS2 and truck LH6 engines in 2005.

The totally new engine control module (ECM),*dubbed E40, still used a processor from the Motorola 68000 series, but a newer and faster version.*
Flash memory size remained 1 megabyte, the same as existing LS1 PCMs, but it was a newer generation of flash. The increases in performance were complemented with a radical reduction in size as well.*
Following the nature of electronics evolution, the new box was drastically smaller than its predecessor, and also featured highly compacted, smaller connectors. The E40 also only controls the engine. Transmission control was separated out to a new stand-alone controller, the transmission control module (TCM), named T42.*

Yet both new units combined were still much smaller than one combination LS1 controller. The new TCM is also a flash-based unit, featuring 1 megabyte of memory.*
This separation of PCM to ECM and TCM allowed for easier powertrain integration between the various platforms utilizing Gen IV powertrains.*
The E40 would only serve two years as a GM controller between '05 and '06.

For 2006, GM introduced two new ECMs,*E38 and E67.*
These controllers look somewhat similar to the E40, but slightly different connectors exist on each of the three, and none interchange.*
The new ECMs featured a departure from the historied 68000 series chip for a new*Motorola PowerPC based 40 MHz, 32-bit RISC processor*and a flash memory bumped up to a hefty 2 megabytes, or 2048 kilobytes-twice that of the replaced controllers.*

They are also the first GM controllers to feature floating-point processing, an improvement to the accuracy in which it makes calculations.*
The E67 has a slight edge on E38, thanks to its additional input/output lines, thus making it the choice for vehicles with variable valve timing.*

Also new for 2006 was the T43 transmission controller for six speed automatics. In another radical move, the T43 found a home 'inside' the transmission. The T43 is actually tucked in with the valve body, and has yet to receive a service part number from GM.

Clearly, GM's powertrain controllers have come a long way over the years, and we expect the ongoing evolution to continue on its advancing path.*
It's been 23 years since Masuoka's invention of flash memory, and 13 years since taking duty in GM's controllers.*
Now it's arguably one of the most important advancements that enabled the mainstream popularity of DIY custom tuning.


_________________________
JR*
True Custom Performance Tuning
Teamzr1.com

'''''''''
End Quote.

This is what I have found in brief about the evolution of the PCMs


-Jonathan

[VetteVet]

Jonathan,

The LS1b PCM is the 411 PCM. I have looked at pinouts for all 411 applications that I can find and none of them have a pin for 8192 UART out, only Class II serial data.

If you are aware of an application for the 411 PCM that shows it is capable of 8192 UART communication, please let me know.

Why else would GM (or Holden) go through the trouble and expense of developing and installing a PIM if the 411 has the hardware onboard?

Based on my research, I am leaning away from any LS PCMs other than the 411. It is a much more capable PCM (and tuning support is WAY better) than the ones used from 1997-2000.

If you'd like, we can take this discussion over to CF to consolidate the info.

I appreciate your efforts.

Jep

[Merlot566jka]

2003 c5 corvette 0411 pcm, pin 14 on the c1 blue connector, tan wire, 800 series UART data for Throttle Actuator Control Serial Data

in the past all 800 series circuits were UART, as is here.

Consolidation wouldn't hurt, although once I have this all sorted out, I think consolidation will be a must.

I got some of the wiring harness pinouts for the swap completed this morning, I will be working on the rest tonight. It seems that some circuits just take a new name, but the data is the same. I will post more on the CF as I go about it tonight.

(and to add, there may be a way to make a swap "adapter" for the pcm's... no need to re-pin everything. I have re-pinned hundreds of connectors...and I hate it as much as I did the first time I did it)