[alanahbing142]

A big part of my business is the repair and rebuilding of DDEC III and DDEC IV core ecms. I replace the batteries, memory, electrolytics, and any other part that goes bad. Then I put the rebuilt ecms though some torture tests on the ECM dyno to test their durability. Each DDEC has to hold it’s Jake brake on for over 30 minutes, run at over 2400 rpm without a misfire, activate it’s cruise control and fan control. This is all done autonomously on the ECM dyno over a 10 hour period. If no errors are recorded I paint it, tag it, and make it available for resale.

[atomic_age]

I routinely buy used DDEC III and DDEC IV core ecms in need of repair but last month a salvage yard I’d purchased from before mailed me five DDEC II ecms and asked if I was interested in evaluating and possibly purchasing them. I told them “I don’t work on DDEC IIs”. Over the years, I must ‘ve said those words a few hundred times. An old habit from when I got into DDEC programming in 2008. At the time DDEC IIs had no aftermarket programming options or support of any kind or at least not in the trucking industry and now almost 10 years later the industry still hasn’t changed. DDEC II owners with motorhomes, firetrucks, sportfishing boats and of course trucks have been looking for someone to turn to. Usually owners of these DDECs are forced into doing an expensive DDEC II to DDEC IV conversion complete with all the added complexity of DDEC IV programming. here

[foxhunter]

So why is the DDEC II shunned? First of all the DDEC II ecm is no longer supported by Detroit. So replacements come from a dwindling supply of used and often unreliable parts. Also diagrams, programs and ECM parts are hard to come by. Repairing an ECM is just like repairing anything else, you need to be able to get the right parts and getting parts for a computer that was made in the late 80s isn’t easy. Especially when many of those parts have a shelf life. The last reason is more of a personal one. The company I worked for from 2007 to 2015 didn’t bring in Detroit’s older than 1994 so I almost never saw a DDEC II. During that period my efforts were directed away from the DDEC II but now that I’m independent I’m free to look into this myself.

[Moredread]

I had kept all the DDEC II units in the box the salvage yard sent me because I was planning on sending them back later that day. After some thought I called up the salvage yard and told them I would buy all five DDEC IIs. Since then I’ve finished building my DDEC II ECM dyno testing harnesses. I can now fire injectors and test all major functions for the DDEC II. I am several months away from being able to repair or program these but this is where learning how to do that begins.

[wbgtrfv]

Injector is brand new - Harness to ECM is brand new, checked and cleaned all ground and power cables - nothing seems to be changing..

[Pegasus-Rider]

I wouldn’t rule out the harness either, even cat screws that up lol. We went through 3 new harnesses trying to get one with the #6 injector wiring that’s crimped right and ended up having to just splice a new pigtail into a brand new uvch because they would just keep getting defective harnesses ? here

[laczoka]

This is best answer you can get as everybody thinks that dealer is GOD who makes no mistakes
One time I head a truck with bad Vpod harness, replacing it made the truck 100% insane, even after doing VPOD EGR/TURBO actuation testing proving my speculations of mixed ground control wires I was to be blamed and the shop who bring me the truck unable to fix the original problem told me I am crazy to even suggest DD will make mistake like that refusing to bring it back so I can reverse the control ground wires. I told him maybe I am crazy but I am not stupid, why did you get new vpod harness then? No answer just a stupid expression on his face What a ass

[BlackEye]

1.) We can display the codes that are in there now but which code displayed would be the last one raised? The first to come out of the ECM or the last? Or is there no order? more

[UnVisible]

Hey Folks,
Thanks to all who make the rest of us look smart. I have a 1994 Freightliner with the Detroit 60 Series engine which has run perfect for the past 5 years. All of a sudden, the engine will start to drop cylinders after 15 minutes and then quit running altogether. You let it sit for an hour and cool down and then it starts right up and runs perfect. We pulled and replaced the fuel filters, emptied the water seperator, blew out the fuel lines and can't seem to find anything else wrong. My thought is that I either have a fuel problem or an electronics problem (as many of you know, electronics can be heat sensetive and fail hot and then go back to working when they cool down). We do have some error codes but they have been there since the first day of the truck because they have never been cleared. We don't have a tool to clear them and start over to see what codes may be possibly generated by this condition. So, the questions I have are:

[ruenma7411]

2.) We only have one RED code (43 - low coolant level) but the engine does not shut down hard (immediately) like you think it would for a RED code. It tends to limp along for a while and slowly die.

[sjaak]

3.) I realize that the symptom I am desribing could be caused by one of many conditions but has any one seen a problem similar to this? My driver (we are a trucking firm) swears that it is a fuel problem. Also, it should not be a contaminated fuel problem because we load from a common fuel tank and the other 8 trucks run fine. more

[tuxsoul]

I would think a communication issue would cause an engine light, or a diagnostic code. What about an incorrect setting on the commander, or in the engine computer? I don't know how it could have changed in the engine computer, but there are things that have to be set to make the commander work. Has anyone had issues loosing settings? can anything be changed on the commander?

[user]

I'm not familiar with the fire commander system. here

[komoto]

But, the comment on the DDEC dedicated battery is a sure possibility of causing your problems. here

[mtve]

I'm the one Fire and Rescue calls, when they need to be Rescued. here