series 60 fault codes

[H3Jim]

The following letter was sent to DD by a friend of mine.  Has anyone seen or heard of anything like this before?


My 1997 Series 60 DDEC III engine (Unit
06R0392140, Model 6067GK28) mounted in a Prevost
H3-45 bus insists upon idling for 15 minutes to 1
½ hours before the check engine light will go out
and allow the engine to accelerate. The codes
displayed are 22 - TPS input voltage low, 34 -
turbo boost pressure circuit failed low, 36 - oil
pressure circuit failed low and 52 - ECM A/D conversion fault.

Factors to consider: The starting batteries are
new and typically measure 12.8 volts each prior
to engine start. Replacing an older set of
batteries made no difference. The engine has
never hesitated to start. The starter has never
exhibited less than full torque. The Delco 270
amp alternator has consistently put out 28.5 volts.

The time from engine start to acceleration varies
inversely with outside air temperature.
Temperatures in the thirties cause long delays
while temperatures above sixty degrees cause
little or no acceleration delay. Codes disappear
one at a time as the engine warms up. On a 49
degree day, code 36 goes out in 8 minutes, 34
goes out in 22 minutes, 22 goes out in 36
minutes, 52 goes out in 38 minutes and the engine
will accelerate when 52 goes out. The engine
coolant temperature gage remains frozen at an
indication of about 170 degrees from immediately
after engine start until code 52 begins to go
out. It then fluctuates full scale, settling down
at a steady minimum reading only after all codes are gone.

The codes do not change after engine start. Those
that are present before engine start are the same
after the engine is started. Warmer temperatures
cause less codes. Above about sixty degrees, only
a code 52 will be present or none will show. If
the 52 is there, the temperature gage will almost
immediately begin fluctuating wildly and stop
when the code disappears within a few minutes.

The fact that codes quickly re-appear when a
fully warmed up engine is subjected to a cool
breeze on the ECM after shutdown makes it appear
the ECM is responding to changes in temperature
at the printed circuit board itself.

Have you had temperature issues with the ECM
itself? What must be done to eliminate the engine acceleration delay?

Thank you for your help.



DD's simple response was that I need to take my
bus to a shop that has a test ECM and let them
fix it.  - probably not bad advice, but anyone with any ideas would be appreciated.

[H3Jim]

so I guess no one has any comments or suggestions?

Thanks for looking

[DebDav]

Guess not.

I have no idea. but I also would like to hear (read) something.

[lloyd]

The reason I would take it to a DD dealer is because they trained on repairing blink codes. They have the proper software on a PC that directs the mechanic through a flow chart depending what results they get from the tests. It sounds like they are all connected, so it could be a ECM or could be as simple as a poor ground. They do have a test ECM that could plug in to the engine and that would tell them right away if that is the problem. Other than that you would be going in circles, and who knows maybe this has happened before and DD is aware of the problem.
Lloyd

[tekebird]

That Sucks.........that code reader is expensive.... prob the only way he is going to fix it is a trip to the DD dealer.

glad I am old school 2 stroke....no damn codes, no damn computers.

[RTS/Daytona]

Jim

Perhaps it's worth a chance to pull the plug-in connectors on the DDEC and:

With the battery Disconect off -
-use a soft (non-conductive Brush and 556 Contact cleaner
-[the only cleaner I really trust - usually available at Napa or Autozone] -
-Be careful many DDEC's are wired to supply 12 volts even with the disconect off - to keep the memory alive

clean the pins and the socket

The fault that really worries me is 52 the A/D (analog to digital) that's all internal DDEC stuff most likely

I would also check and clean ANY ground strap or connection that you DDEC could be using near the computor

Good Luck -

Pete RTS/Daytona

[Len Silva]

Jim,

I don't know much about the S60 ECM but I do have years of electronics trouble shooting.  Try this: On a cold day when you would expect all those codes, try warming up just the ECM with a hair dryer or something.  Get it good and hot then try a start.  That should help narrow it down to the the ECM or other problem.

Len

[Sammy]

Jim, the first thing I would do is shut off the battery switch, disconnect all the cables on the negative side of the battery on the left,in your battery compartment.Remove,inspect,clean all other battery cable connections.Leave the negative side disconnected for now.
Next, disconnect the 30 pin connectors on each side of the DDEC computer (ECM).There will be one small bolt in the center of each 30 pin connector that secures it to the ECM-1/4 inch socket fits perfect. Inspect all terminals inside the 30 pin connector, inspect pins in ECM for corrosion,damage,etc. I use a small mirror sometimes to inspect the ECM terminals without removing it from the engine. I use a small amount of dielectric grease on terminals before securing the 30 pin connectors back onto the ECM. Do not overtighten the small bolt that holds the 30 pin connectors to ECM.Looking at ECM on your coach, the connector on the left - closest to the rear of your coach is the engine harness side. The connector closest to the battery compartment is the vehicle side.
The TBS,OPS are supplied with a 5 volt signal on wire 416 of the engine harness,terminal W1. The plastic 30 pin connector housing only has letters on one side of it, gotta look close. The terminal closest to the letters is 3, 2 being in the center, 1 furthest away of course.
So, W1 will be in row W, furthest from the side of the connector with the lettering on it. Should be a gray wire.
The TPS gets power from wire 916 on the vehicle side connector, at terminal A3.Should be a red wire with a black tracer.
Once you have checked these wires,terminals and connections real good, secure the cable connections at the batteys.
Turn on your battery switch and try it again. Let us know how you make out.
I wrenched on H series Prevosts for 12 years. Good luck with your troubleshooting tasks.
Sammy

[H3Jim]

Thanks guys for your thoughtful and informative answers.  Here is my friends repsonse, although I half expected him to leave a message himself.

I just checked the MAK board and was really impressed with Sammy's
answer. He's had some valuable experience. I'll try cleaning the plugs as he suggested (perhaps tomorrow) and get back with you. I already tried heating the ECM with a hair dryer, but in the cold breeze, I couldn't get it warm enough to call it a valid test. It might be worth another try.

[RTS/Daytona]

FYI

Ebay DDEC III

--> http://tinyurl.com/37kmlv

Pete RTS/Daytona

[ronwalker]

H3Jim, Thanks for your help. Yes, I should quit lurking and post for myself. Okay, guys, this is my first post - please be gentle.

I did as Sammy suggested, cleaned the battery connections and grounding terminal - no corrosion there. I inspected, cleaned and applied dielectric to the ECM plug pins - found no corrosion there. I checked the blink codes again before engine start and the same four were present. This time it took an even TWO HOURS of idle time before the codes disappeared and the engine accelerated. At 600 RPM, I'm sure DD would have comments about my long slow idling periods.

Right now, I'm on a mission to get to Tacoma, Washington ASAP. I'm stopped at a Flying J (with the engine on fast idle) and will hit the road again as soon as I post this. I may still opt to bid on one of the $225 to $325 ECMs on EBay since I probably can't even have mine checked for that price, but I still have one nagging concern. The fact that the engine coolant temperature gage is frozen at 170 degrees until the engine warms up to a certain point, swings erratically from stop to stop, then settles down to indicate the proper temperature really bothers me. I can't help wondering if I have a temperature sensor wire that is shorting out til it warms up or some such thing. Of course, I have no idea if that would cause my codes either. Then there's that "wicking" problem that is bringing oil from the top of the engine through the wire to one of the upper plugs on the ECM. The books I have don't say if that weird problem will cause codes to appear either. Obviously, I'm just not living right.

Thanks for all the help. Some of us need it more than others.    Ron 

[Dallas]

Welcome to our madness RonWalker!

We have a pretty good group of people here and we promise we won't take more than a pound of flesh!

We hope to hear from you more, maybe let us know what the final outcome of the problem is and possibly post some photos.

Here are a couple of ideas, since Sammy's ideas didn't seem to help:

In the olden days, when I was ASE certified, one of the standard tests was called the wiggle test, in which you grab likely wires  and wiggle the S**T out of them, pushing, pulling, twisting and turning until something happens.
It doesn't always work, but sometimes it lets you know where to start looking.

Another thought is on the 'Wicking' problem. Is it possible the wire is shorting out at the other end from the ECM? Why not make a temporary jumper and bypass that wire to see what happens?

And, finally, an off the wall thought, since the problem seemed to get worse when you did the cleaning and greasing, is it possible there are loose pins in the ECM itself, even though they are potted, breaks still happen and would probably show up with the expansion and contraction of heat/cold cycles.

OK, that's my two Dinars worth, I hope you get it fixed soon!

Dallas

[edroelle]

Ron,

This is a long shot.

In addition to the wiggle test, there was a "tap" test on automotive ECMs.  In fact, there was a service bulletin of this "tap" test to help diagnose the problem.  In the early 90s, there was a problem of cracked solder on the electronic boards due to vibration and the heating and cooling cycles.  I do not know if the diesel ECMs had this problem though.

While the engine is running, tap the ECM.  I have seen dented ECMs from over-zealous mechanics.  Don't go that far, but you may need to tap smartly.

Ed Roelle
Flint, MI

[niles500]

Ron - I wouldn't worry so much about the idle time with the 4 stroke - not the same problems as the 2 strokers

[ronwalker]

New clues!? I'm on a whirlwind trip from Arizona to Washington state via Florida. The 5000 mile round trip to FL was flawless except for the morning acceleration delays. However, the colder temperatures on the way north through Utah brought a new surprise - blink codes and throttle-to-idle from a steady state cruise! How embarrassing to be at idle on the shoulder of the road while your engine warms up again! A little trial and error showed I could cruise at 45, but not 50 MPH and the engine will run at 41 degrees, but not 39. While downhill stretches will usually cause codes to appear along with a fluctuating coolant temperature gage, the engine will continue to operate at cruise RPM if the cruise control is on. Touching the foot pedal will cause the gage to freeze at 170 degrees, the check engine light to come on steady and the throttle to close. I limped into Salt Lake City's DD service center because this routine isn't going to hack it in the higher elevations between here and Tacoma, WA. Before the DD guys shake my hand and take my credit card on Monday, I hope to disassemble, clean and inspect the TPS, locate the coolant temperature sensor and check its plug and wires, do Dallas's wiggle test on the entire harness and Ed's tap test all in the refreshing 19 degree morning air. I haven't given up hope of blundering onto something that magically fixes everything for free, but I'll replace both the TPS and temp sensor and do an ops check before forking over thousands for that shiny new ECM.

Dallas, it appears the valve cover must be removed to check for shorts on that end of the wicking wire. Major project! DD told me half of my cylinders will probably quit firing, but maybe not right away. The ECM pins appeared really solid, but the best inspection will be with the ECM removed. Thanks for the warm welcome. I'll try to keep the next post shorter so you don't change your mind.

Niles, thanks for easing my guilt a little.    Ron