Right, so i am currently starting to swap out the original ecm on my RS with a 16197427 PCM. So far so good, have the new ecu sat on my lap with a calpac thats for a manual l03. This should be the easiest way to get my stock motor running with this ecu. Oddly enough the bin i have cant be found on the diy efi or on gearhead-efi but is really handy if u have an RS and want to tune the motor without forking out $$$ for the Autoprom. Il upload it of course once ive got to that stage...
So my plan is to stick a NVRAM in place of the EEPROM and change the code to enable tuning through the ALDL port. However ive run into a problem straight off, it seems gm used custom chips in the ecu some have DELCO written on them and i cant get the datasheets for those. Also the microcontroller is also unknown, people have said its a 68hc11, well i cant find any info about the chip on the board. So im wondering if someone can help me verify this. Also i havent seen a schematic, also wondering if someone has one.

This is a simple pcb so all i need is chip info and il make u one in a nice pdf format as well

I realise this is a tall order to ask but i could well offer a PCB and some code for a NVRAM solution for this PCM. I am an electronics engineer and this stuff is simple ancient stuff, just i need more info

 

The EPROM is the basic 27C512 unit.

The CPU is the GM P6 model. It is similar to the 68HC11, but modified specifically to GM requirements. IOW, it's custom.

RBob.

 

Yes that is what it seems, so i am wondering since your the guy that makes the ebls, how did you find the info to be able to interface to the cpu? Without datasheets its just a black box like all the rest of the delco chips on there.

 

There are schematics of some of the ECMs. That was enough to get me started. Then through experimentation was able to figure out other pins/parts of the various chips and how they worked and what they did.

Reading through the code that interfaces with the hardware also reveals a lot.

RBob.

 

I have replaced old TBI and TPI ECMs with the 427 PCM. It is a major improvement and allows the use of 4L60E and 4L80E transmissions.

For ALDL updates, you can replace the PROM with an NVRAM (search pcmhacking.net) for the module VL400 sells or do this for $10.

http://pcmhacking.net/forums/viewtopic.php?f=33&t=1560

Next you need to add a few jumper wires from the edge connector of the PCB and pcmhacking shows how and where to add the wires.

Now that you have usable hardware, you will then need to add software to do the realtime ALDL updates. There is software on this forum to do it (JP86SS).

The 427 ECM has lots of extra RAM that is unused and ROM CODE space that is unused. I have added new functions and have been running it with E-trans and boost for years. The ALDL is reliable.