Need Help DDEC II

[Sam 4106]

Hi guys,

Sorry for not getting back until now. We got a can of contact cleaner and cleaned all the connections at the ECM and at the TPS. We are at Interstate Diesel in Sioux Falls now waiting for an ECM. It should be here in the morning. We got about 30 miles north of Sioux Falls this morning before having problems. Cruise kicked out and no throttle response until I let up on it and depressed it again. It was 59 degrees. We stopped at a rest area and decided to return to Sioux Falls since we had seen a sign for them. On the trip back to Sioux Falls the bus ran without incident. They got us in the shop about 1:00 PM and hooked up a reader, getting a lot of codes. From that they decided to put on a test ECM and take a test drive. We only went less than a block and had almost no power so we returned to the shop. A little digging determined that the test ECM was for a 6V92. They claimed that the only way to tell that was to try it. That seems hard to believe. Anyway the only alternative they offered was to order an ECM. We will see in the morning if that solves the problem.

On another note I discovered this morning that our belt drive alternator has a bad bearing. It was singing really loud. So I will have them remove it to see if it is just a bearing as I suspect. If it is more than a bearing, I will have them leave it off until we get to Dickinson, ND and have it repaired there. The ECM is powered from the house batteries so I think I can drive all day. Or, I  can run the generator to keep all of the batteries charged.

Sean, thanks for the offer of the reader. If I had read your message earlier I certainly accepted your offer. My, you sure do get around.

Thanks for all the help, Sam

[belfert]

Are they really sure the ECM is bad, or are they just throwing parts at it?  Your problem doesn't seem to be consistent so a new ECM may start acting up a few hundred miles down the road.

[hargreaves]

I would throw a new TPS sensor at it before an ECM. It is very unusual that an ECM would cause that problem.  The TPS sensor is an easy swap. Two screws on the side of the throttle pedal.  If you hook up an MPSI reader you should see the throttle counts go to zero when the incident happens. 

Cheers Gerry

[PCC]

Just got through the same situation.

Three things you might add to your diagnostics

1 - Does the cruise work without any problem or does it also drop out on occasion?
2 - Does the problem only occur after you have been running for 30 minutes or more?
3 - Is it getting progressively worse, like it only happened rarely a few trips ago, but now is becoming more consistent?

I replaced my TPS, and the wires from the TPS to the computer. Neither fixed mine. It ended up being the DDEC ECM.

Answers
1 - If the cruise works without a problem, then it is most likely the ECM
2 - Heat build up within the ECM (driving time) causes components in the ECM to become intermittent.
3 - Increased failures means that it is more a computer component failing than an outboard component (TPS, wiring, etc.)

Hope this helps???

[Sam 4106]

Hi guys,

The problem is solved, a reconditioned ECM was the solution. We were treated very well at Interstate Detroit Diesel in Sioux Falls, SD. They made a stressful situation a little less difficult. They worked us in to a busy schedule to diagnose the problem, had a mechanic that had worked for Jack Rabbit Bus Line since 1976 until they closed and now works at Interstate in the same shop, and let us stay in their lot overnight

with a 20 amp cord to keep the batteries charged. They got the ECM overnight and installed it by noon. We took our bus on a test drive while they had lunch and got us on our way after that. Even though the bill was hard to swallow, $2537.16, their shop rate at $102/HR was in line with other shops. One hour was for checking another item. I wish we lived nearer to Sioux Falls so I could seek advise from their mechanic as needed.

We are now in Hettinger, ND city campground preparing to go to an RV rally about 30 miles from here this afternoon. Hopefully the rest of our trip will be without incident.

Thanks for the advise and help, Sam

[Iceni John]

From that they decided to put on a test ECM and take a test drive. We only went less than a block and had almost no power so we returned to the shop. A little digging determined that the test ECM was for a 6V92. They claimed that the only way to tell that was to try it.

If/when some of LA's and Rialto's buses like mine are scrapped, would it be worth it to buy a used DDEC II from them as a spare for my bus?   Will any DDEC II for a Californicated 6V92TAC like mine work on any other 6V92TAC, or do they each have to be individually set (programed?) to a particular engine?   The reason I'm asking is that a DDEC failure is not something I can bandaid to get home, so having a spare may be a good idea.

Thanks, John

[PCC]

Not totally sure, but many ECM units are programmed to the engine. They may be interchangeable, but not act exactly the same.
But having a spare to at least get the bus home and not stuck on the side of the road is very worth considering.
Glad you got it fixed.

[rv_safetyman]

For sure, there can be significant differences between software in the ECMs.  When I replaced my failing Series 60 engine with a newer version, I put the first engine ECM on the"new" engine and beat my head against the wall trying to get it to run properly.  Turns out that DD changes the MAP sensor (detects boost) and my old unit was programmed for the old GM type sensor.  When I changed the ECM (correct one for the engine), everything worked fine.  Lest you think me stupid , I used the original ECM since it was programmed for the AutoShift communication and I was afraid the "new" ECM was not.

The best solution is to find a spare ECM and take it to DD (or one of the "black market" folks) and have your software installed on the spare ECM

Ran into the same problem on my transmission ECM.  The spare unit was programmed for a different set of gear ratios and it would not work.  Had it reprogrammed by the Eaton rep and it now works fine.

BTW, if you have a DDEC II there is a DD conversion kit for upgrading to DDEC III/IV ECM.  The PDF I have says the part number is 18SP546.  That does not look like a DD part number to me, but the data sheet lists that number.  It says it is for an upgrade for Series 60, but I bet it would work for 92 series as well.  I would think the DDEC III/IV ECM would be more robust and easier to find.  It does not have fuel cooling.

Jim

[Boomer]

Jim I wonder if you might be able to email me that bulletin.  I inquired at my local DD distributor about changing to DDEC III from II on my 6L71TA.  I reasoned that a 6V92 or 71 ECM might work.  They said no dice.  Can upgrade a III to a IV though, but assume that is S60.  Pittsburg Power can reconfigure mine though.  Thanks.

[rv_safetyman]

Mark, I had meant to send you that bulletin after our discussion at the Cody Eagle Rally - sorry.

The last email address I have for you is at "airspd", is that still current?

I had hoped to upload it to Photobucket, but it is a PDF, so could not do that.

Jim

[Boomer]

That's it Jim.  Thanks.

[rv_safetyman]

Mark, PDF sent.

I had not spent much time looking at the 8 page document.  Lots of details, including how to add three sensors.

As I said, it is listed for Series 60 engines, but I can't think of a reason it  (or the information contained in the document) would not work on your 671 if you have/can locate the computer resources to reprogram the ECM.

I would like to follow your progress on this conversion. 

Jim

[luvrbus]

I bought 2 new DDEC III ECM's from Crane Carrier in Tulsa for the rh 6L71 you should be able to find the III for the lefty the firing order is different on the 6L71 from the series 60 even with both being inline 6 cylinders it's the way the DDEC sends the firing order.

The DDEC III's I have the firing order is 352415 I think Cole told me the lefty engines fire 263514 and the 60 series fires 153624 I have no idea what he is talking about I just told him to make it work for a lefty 

I found 1 at a marine shop and he wanted a small fortune for it so we went another route

[Don Fairchild]

Clifford, I need to get ahold of cole would you mind shareing his contact info with me. I need several ECM's reprogramed and DDC wont do it any more.  Help

Thanks

Don

[Boomer]

Clifford I assume the 6L71 ECM's are marine, correct.  Can't feature a lefty industrial.  If you communicate with Cole can you ask him where I can find a III for me.  Thanks.
Mark