Probably not for those who aren't interested in computers and electronics, but I have decided to figure out for myself how the engine computer and associated things work. If anyone else is interested, I'm keeping a web page updated as I go along at http://vs18k.dyndns.org/cecu/Dodge_Cummins_ECU.html

 

Very interesting. Would be cool as hell (and you would make tons o cash) if you could come up with something like EFI live for the VP generation cummins. I got a laptop and almost identical truck so if you need any help off an 02 shoot me a pm. I'll beta test it when you get to that point as well lol

 

Very cool keep us updated!!

 

Very, very nice!
I will watch this thread. Playing with MCUs was my hobby until the day job took over I am very curious and will be following your research.
Of course, timing and fueling tables are what gets changed by programmers such as Smarty. However, they can not read the contents of EEPROM, just like you had trouble doing at first, and can not save the initial programming of the ECM. Maybe you can address this problem using buffered read and help out those who are paranoid about keeping the original programming.
-P

 

Very interesting Jdonoghue

Def. going to keep track of this topic!

 

here is a blast from the past

When I used to ship ecms to Marco for CaTCHer updates, Custom must of wonder what the heck is in here







no note of nothing, it was just tossed back with the others

 

That's a great web page you have there. Keep up the good work.

 

I think they heard of us BOMBING our trucks, so the wanted to check things out!!!!!!!!!

 

I find this search engine useful for electronic components:
http://octopart.com/
Most were found and I included a link to data sheets. Good luck in your effort.
Dave

LM2901
Low Power Low Offset Voltage Quad Comparator
http://www.national.com/mpf/LM/LM2901.html
LM2903
Low Power Low Offset Voltage Dual Comparator
http://www.national.com/mpf/LM/LM2903.html
74HC4051
8-Channel Analog Multiplexer
http://www.fairchildsemi.com/pf/MM/MM74HC4051.html
74HC74
Dual D-type flip-flop with set and reset
http://www.standardics.nxp.com/produ...74.74hct74.pdf
74HC14
Hex Inverting Schmitt Trigger
http://www.fairchildsemi.com/pf/MM/MM74HC14.html
74690
?
8L12A
3-TERMINAL POSITIVE VOLTAGE REGULATORS
http://pdf1.alldatasheet.com/datashe.../H78L12AA.html
SPI EPROM
?
MC68336
ecu
http://www.gaw.ru/doc/Motorola/33676UM.PDF
28F400
4-Mbit SmartVoltage boot block flash memory
http://www.intel.com/design/flcomp/s...s/29053805.pdf
3029009 1951130
?
INTEL 82527
Stand-Alone Controller Area Network
http://www.intel.com/design/auto/82527.htm
PHILLIPS 4651148 005633 Fhr011B
?
AMTEL ENCORE 51R42722U02 82002253=001 A9D0013 9951
?
http://www.atmel.com/products/product_selector.asp

 

Thanks for the links. As for the EEPROM, it's an Atmel part, I have the data sheet here. Most of my time now is being spent on the disassembly listing of the code. I really need to find a junkyard ECU so that I can trace the inputs and outputs and find out which pins the various signals go to - like where the MAP sensor input goes, etc.

I also discovered that they wrote custom microcode for the TPU (time processor unit, part of the microprocessor), this gets loaded at startup. I had to write my own special disassembler for that. I think the crank sensor, cam sensor, and reference signal from the VP44 go into the TPU inputs, but I really need to trace those signals to figure out for sure.

Oh well, it's just like a giant, strange puzzle....

 

Wow intresting project. I just started school for electronics tech, and find this very intresting. Maybe in a few months i will be able to follow it with a better understanding. Good Luck I will follow you progress

 

This is interesting to read, which box controls the shifting of transmission, the one on the engine or the one on firewall?"

 

PCM on the firewall

 

My ECM has recently gone bad. My local diesel mech told me that it is going to cost me $1200-1300!! He said that it would have to be flashed from Cummins, and they also charge a core charge on top of that! Is this true, or is he trying to shaft me? Is there an alternative?
I have a 2001 3500 dually with 6-speed, 60-horse injectors, and an Edge module, and a lift pump kit. (Many more mods to come!) Is it possible to get an after-market deal that works better, maybe produces more hp?

 

I found the part of the code responsible for generating the SAE J1939 messages. This has allowed me to figure out a lot more of the mysterious program! I still have a lot more work to do, but it is getting much more interesting! I should be able to identify where things like engine speed values, etc. are generated (from sensor inputs and maps).

Still need to figure out how the reprogramming (reflashing) works. At worst, I can solder an EPROM into it, but I don't really want to have to do that if I don't have to.