Bus Conversions dot Com Bulletin Board
September 20, 2014, 12:59:08 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an E-Mag Subscription: It takes up much less space in your bus.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: 1 2 [All]   Go Down
  Print  
Author Topic: 8V92 DDEC1  (Read 4202 times)
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« on: October 24, 2009, 05:18:58 AM »

I am the slave to my 8th coach; a 1988 Prevost with 8V92 DDEC1.

New engine has 40K on it, and after driving it for a few months, it developed a hiccup, like a sensor shutting the engine down for less than a second, but only at idle.

Then one day I left the batteries on overnight, and had to recharge the batteries. Started the engine and no hiccup, until I closed the battery drawer.

I shut the engine down, and re-opened the battery drawer to find that the 12v cable had been installed leaving the terminal the wwrng way, and the wire had been rubbed raw against the stainless steel framework and shorted out. (Left a 2" hole in the frame)

So I corrected that problem, and now it will not start at all.

Could that short have damaged the DDEC1 ECM? They tell me that those units are like a tank, but I cannot find anything else that would cause the coach not to start.

The ECM is a very old model; can it be replaced with a later/different version?

When I began trouble-shooting the no start, I did find the breaker (5A) to the ECM was tripped. I reset that, but it still will not start.

I have done too much work on this coach to stop now, so I hope to get some ideas. This is a new one on me, but then, in this realm, isn't every day a day of discovery !!!
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
luvrbus
Hero Member
*****
Offline Offline

Posts: 12496




Ignore
« Reply #1 on: October 24, 2009, 06:02:41 AM »

Check your ground and power supply for 11.5 volts probaby just a fuse and you can upgrade to a later DDEC if you choose 



good luck
Logged

Life is short drink the good wine first
robertglines1
steam nut
Hero Member
*****
Offline Offline

Posts: 4008





Ignore
« Reply #2 on: October 24, 2009, 06:04:02 AM »

check to see if the breaker is bad jump around it temporary..I have a 89 pre 8V92.... Also ck to see at least 24 volts on batteries..also inside the passanger side rear bay on frame rail there are another set of breakers just before your 12volt or dedec controll switch....I have forgotten to turn this switch on before and the engine will crank but won' start.Also the control box located in the same area bolted to the ceiling has a reset button it...You can go to prevost coach and download a wiring diagram to your coach .....need serial # last 4or 5 numbers I think. Good luck..let me know what you find.....ck rear front start position on your rear junction box.
Logged

Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #3 on: October 24, 2009, 04:24:06 PM »

Thank you for your responses. I have the wiring diagram, and have spoken with mechanics, and Detroit Diesel, and everyone is purplexed by this.

All voltages are all good, so am I understanding that these ECM units and the EDU, are reasonably fireproof? If so, what else could shut down the system?

Anyone's thoughts.

Thank you
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
luvrbus
Hero Member
*****
Offline Offline

Posts: 12496




Ignore
« Reply #4 on: October 24, 2009, 05:06:40 PM »

Have you checked to be sure that the engine is getting fuel
Logged

Life is short drink the good wine first
Busted Knuckle
Hero Member
*****
Offline Offline

Posts: 6447


6 Setras, 2 MCIs, and 1 Dina. Just buses ;D


WWW

Ignore
« Reply #5 on: October 24, 2009, 05:14:03 PM »

PCC,
There should be 2 wires going from just 1 battery (12 V) for the ECM.
More than once on MCI's & Setra's I have found the inline fuse holders on these wires to be bad.
I've seen them badly corroded and not making contact, wire broken in the hard plastic and so on. I'd temp bypass the inline fuse and try it.

I saw you mentioned a breaker, I'm not that familiar with Prevost. It could be they have a breaker instead of inline fuses. If that is the case I'd bypass the breaker. If it works you know where the  problem is.

Maybe some of our DDEC wiring gurus can chime in and help with post #'s etc and you could go straight from the battery to the correct posts on the DDEC. If it then started work yer way along the path til you find yer short.
FWIW Grin  BK  Cheesy
Logged

Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

Grin Keep SMILING it makes people wonder what yer up to! Grin (at least thats what momma always told me! Grin)
Busted Knuckle
Hero Member
*****
Offline Offline

Posts: 6447


6 Setras, 2 MCIs, and 1 Dina. Just buses ;D


WWW

Ignore
« Reply #6 on: October 24, 2009, 05:14:42 PM »

Have you checked to be sure that the engine is getting fuel

Good point also Clifford! Grin 
Grin  BK  Grin
Logged

Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

Grin Keep SMILING it makes people wonder what yer up to! Grin (at least thats what momma always told me! Grin)
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #7 on: October 24, 2009, 05:17:00 PM »

Thank you for the fuel suggestion. I have a friend coming by to be sure that the fuel tank, while not empty, is not leaning forward sufficient to move the fuel away from the pick-up; it is a kneeling coach.

I understand that the fuel is used for balast, and so a minimum of 5" in the tank is required, or the sensor will shut down the engine, and the tank sits over the front axles.

I love converting coaches, but these mechanical dilemas sometime get the best of me. Gald I can come here and ask my questions of those who have been here before.

Thank you
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #8 on: October 24, 2009, 05:24:10 PM »

Another issue with my coach is the DDEC DDL terminal does not have any data wiring, so the tester simply read "No Data"

Does anyone know which terminals from the ECM are for data, so I can wire these terminals to the DDL connector for testing?

The data is supposed to appear on DDL terminals J & K, and these terminals have no wires at all !!

Thank you Prevost - DD instructed them to install these wires, obviously after my coach was built !
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
expressbus
Full Member
***
Offline Offline

Posts: 156





Ignore
« Reply #9 on: October 24, 2009, 05:36:06 PM »

PCC,

I have a Prevost but have not encountered your problem. Now having said that I can tell you I did have an experience with the coach not starting. Someone mentioned the front/rear start toggle and button. I was doing work in the engine bay and did not want to go into the coach and start it then come back out, then go back in. you get the picture. Well I flipped the toggle on the outside right hand of the 24 volt cabinet in the engine bay to rear start. The push button worked just fine and when I was finished doing the work, which was cleaning the oil off the fan blades, but that is another story, the engine would not fire from inside the coach. I too was very perplexed as to what I had done. Turns out the toggle switch, in the adverse environment it lives in will actually get dirt, oil, corrision you name the method of losing contact between the blades and it can be found in the engine bay. Cheap way to fix it is to throw the toggle bottom to top back and forth several times. This usually cleans the contacts enough to get you back in business again. Hey, if nothing else you are not out any money for having tried it.

Saw you had to charge the batteries. It is also possible reading the voltage at the batteries is not giving you the information you need, in fact it may be misleading you. Battery voltage needs to be tested under load to determine if the battery is good or bad. You could be seeing a high enough voltage with a volt/ohm meter that you conclude the battery is good but have insufficient voltage to crank the engine. I also think there is a voltage below which the DDEC I will shut down so no harm comes to engine or transmission. That bears checking because I do not have DDEC I in my coach.
Logged

Will Garner, Jr
Southern Pines, NC
1991 Prevost Conversion by Country Coach
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #10 on: October 24, 2009, 05:47:35 PM »

Voltage sensor??

So when I first tried to start it, with low voltage, it would have shut down. After I re-charged the batteries, and had enough voltage, does it reset itself?

I know it spins well now, and starts on ether.

I have so many more ideas now - I needed something to do on Monday !!

Thank you
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
rv_safetyman
Hero Member
*****
Offline Offline

Posts: 2199


Jim Shepherd


WWW

Ignore
« Reply #11 on: October 24, 2009, 05:57:38 PM »

Pete Papas was kind enough to send me this information:
Logged

Jim Shepherd
Evergreen, CO
85 Eagle 10/Series 60/Eaton AutoShift 10 speed transmission
Somewhere between a tin tent and a finished product
Bus Project details: http://beltguy.com/Bus_Project/busproject.htm
Blog:  http://rvsafetyman.blogspot.com/
gyrocrasher
Full Member
***
Offline Offline

Posts: 108




Ignore
« Reply #12 on: October 24, 2009, 06:58:07 PM »

Voltage sensor??

So when I first tried to start it, with low voltage, it would have shut down. After I re-charged the batteries, and had enough voltage, does it reset itself?

I know it spins well now, and starts on ether.

I have so many more ideas now - I needed something to do on Monday !!

Thank you

Forgive me if I am being obtuse; but if it starts on ether, does that not indicate a fuel problem? Huh
Mitch
Logged
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #13 on: October 24, 2009, 08:20:36 PM »

Yes, Mitch - It is either fuel, or ECM - Wish I could be sure, so I am going to check fuel first, though with a voltage problem, like the ECM shuts down and does not reset, the engine will get no fuel.

So I keep eliminating the possibilities.

Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
robertglines1
steam nut
Hero Member
*****
Offline Offline

Posts: 4008





Ignore
« Reply #14 on: October 25, 2009, 05:13:10 AM »

with my 89 prev it is very sensitive to water level and oil level both will keep you from starting.will turn over and not start..again if you find the problem please post'
Logged

Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana
robertglines1
steam nut
Hero Member
*****
Offline Offline

Posts: 4008





Ignore
« Reply #15 on: October 25, 2009, 06:18:50 AM »

Me again I didn't tell you but my 89 was sitting in front of the garage door wouldn't start..came in late from very short trip shut it off to use keys to unlock door... would not restart guage showed 25 volts but when i cranked it would fall a lot.. did not start...being dressed up and low on tolerance I walked away...got up this morning read post and decided to ck water and oil levels first.ok! Engine still turned over but did it slower than normal.no start??? hooked up battery charger(have one out of bass boat that charges 4 batt at once on different 10 amp circuts) in less than a minute the engine fired..The charger also tells the condition  of indivual batteries and shows one is real weak..the are less than 2 yrs old.. no matter out they come later to be tested indivualy...one weak batt might be the one feeding the 12 volt to operate the control system or pulling the required voltage over all to a point the control system will not operate...My bus in garage waiting for me to get batteries tested...(load tested)...Go back to original problem ....might just have damaged the one battery or all of them...
Logged

Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana
robertglines1
steam nut
Hero Member
*****
Offline Offline

Posts: 4008





Ignore
« Reply #16 on: October 26, 2009, 09:05:02 AM »

update from my previous post from 89 prevost.. all batteries showed 13 plus volts but when they load tested one battery was bad..so can't go by voltage alone..
Logged

Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana
Don Fairchild
Hero Member
*****
Offline Offline

Posts: 759




Ignore
« Reply #17 on: October 26, 2009, 10:44:13 AM »

DDEC-1 uses a two computer system so don't forget to look for the other computer some where in the bus. If you have a run box, IE front rear start make sure the switch is in the proper position, also the DDL may be in that box. Also check your grounds, if any one is bad it will not start. Remove your ground cable for about 3 minutes and see if it will reset the computer.

Hope this helps

Don
Logged
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #18 on: October 26, 2009, 05:37:38 PM »

Don,

I have the ECM and the EDU. The EDU sits on the top of the engine while the ECM is in the engine control compartment.

Are these the "two computers" you are refering to??

Thank you.
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
Skykingrob
Full Member
***
Offline Offline

Posts: 234




Ignore
« Reply #19 on: October 26, 2009, 06:40:51 PM »

PCC
I experienced the samething with my 91 Prev. It would fire and run for a short time on ether but would then die. I came to the board, like you, and was told sounded like a fuel problem even though I had done nothing to the fuel system to make the engine loose prime. I checked both fuel filters, both were full, I had shut off the fuel line to prevent loosing prime when I checked the fuel filters, you name it, there was just no evidence of a fuel problem. Well, the boys on the board were right. I kept feeding it ether and cranking, after 20 minutes, it started and has run fine every since. I cannot tell you why it lost prime, I cannot tell you why all the filters were full and yet it would not start. I go out now and start it monthly, run for 30-40 minutes and so far, no further problem. Hope this might help.

Rob
91 Prevost LeMirage XL
Missouri
Logged
Ednj
Hero Member
*****
Offline Offline

Posts: 997


Ed & Sue Skiba




Ignore
« Reply #20 on: October 26, 2009, 07:54:31 PM »

Does the DDEC have a Cam Position Sencor (cps)?  Huh
Logged

MCI-9
Sussex county, Delaware.
See my picture's at= http://groups.yahoo.com/group/busshellconverters/
That's Not Oil Dripping under my Bus, It's Sweat from all that Horsepower.
----- This space for rent. -----
hargreaves
1987 MCI 102A3
Sr. Member
****
Offline Offline

Posts: 299





Ignore
« Reply #21 on: October 26, 2009, 09:01:55 PM »

PCC you say you have the wiring diagram. Find out what wires power the ECM, If it anything like DDEC 11 they are the middle set of connections, Get a connector that is the same as the power connector and make  a wiring harness that you can connect to a separate 12 volt battery. this will eliminate all of the bus wiring. If it runs you know you have to chase it down in the coach. If it doesn't run try another ECM.  Good luck           Gerry
Logged

now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia
Don Fairchild
Hero Member
*****
Offline Offline

Posts: 759




Ignore
« Reply #22 on: October 28, 2009, 10:15:17 AM »

PCC;

Yes that is what I am talking about.

Don
Logged
PCC
Sr. Member
****
Offline Offline

Posts: 495


Serving Those Who Have Served


WWW

Ignore
« Reply #23 on: January 24, 2010, 05:54:26 AM »

It was last October that I joined this site because I had an issue with my bus not starting (this thread).

Many of you offered things to check, which eventually brought it down to the ECM. I finally found a company (WWWilliams) in Ohio (I am in Texas) who would actually test my ECM, which did prove to be dead; so dead that they could not even see the programming.

They programmed and sent me a new ECM. Last Friday, I started the engine on the first hit of the starter.

I just wanted to thank you all for your involvement in my project, and for the continued encouragement that I read throughout the posts on this site.

Keith
PCC
Logged

For some, patience is a virtue.
Dealing with me, it is required.
Thank God - He is always patient.
buswarrior
Hero Member
*****
Offline Offline

Posts: 3571


'75 MC8 8V71 HT740




Ignore
« Reply #24 on: January 24, 2010, 06:35:30 AM »

Thanks for closing the loop with the solution!

happy coaching!
buswarrior
Logged

Frozen North, Greater Toronto Area
DaveG
Hero Member
*****
Offline Offline

Posts: 539




Ignore
« Reply #25 on: January 24, 2010, 08:43:31 AM »

Thanks for closing the loop with the solution!

happy coaching!
buswarrior

Yes, thanks. It is nice to hear the final outcome on things...too many threads are left open and us wondering.
Logged
Pages: 1 2 [All]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!