Hi, Long time lurker, first time poster. As title states, engine turns but does not show a check or stop engine light in dash. So far, I am unable to locate fuses/breakers that send power to the ECM. I found on a forum search, a photograph of three fuses at the rear of the engine (front of the bed) The photos were of a 97 U320. Mine is a 95 U320 M11. Any advise would be greatly appreciated. Not in a panic as we are not on the side of the road, but we do need to get this resolved. Thanks to all in advance. :))
Sorry, I meant to say that I cannot locate these fuses on MY coach. I do not see them where the photo indicates.
Thanks
Update: Found three in-line fuses in the vicinity. Two of mine were only accessible from underneath the coach. Bad news, all were good, seated properly, and had current flowing all the way through them. I believe my next step is to pull the ECM and have it tested. I will do so in the morning unless anyone has any better ideas. I am on Alaska time so if any of you folks see this in the morning it will not be too late to chime in as I am four hours behind the east coast.
Thanks All
Was the coach running ok and just quit? Was the engine surging or idling rough prior to it not starting?
Before you removed the engine ECM you may have a bad cam position/engine position sensor. The engine position sensor is located behind your air conditioner compressor & in front of your air compressor. Yes it is hid in a little hole. If you look down through the A/C compressor belt you can see the wire loom. The sensor is screwed it the block actually pointed toward the rear of the coach.
We were told by Cummins that the first generation of wire insulation that they used was sensitive to oil & would deteriorate over time the new ones have a different insulation to cure the problem.
If both sides fail (it has a primary pick up and a back up) it will leave you setting on the side of the road. If this happens you may not get a warning light or a flag on the ECM.
Here is the best pic. I could get. The first is of the plug looking through the belts. The second is the sensor looking from front of coach to the rear
http://www.foreforums.com/index.php?action=dlattach;topic=22487.0;attach=26513;image
http://www.foreforums.com/index.php?action=dlattach;topic=22487.0;attach=26515;image
You need to check the oil pressure sensor also. If it fails the engine ECM won't allow the engine to start as the ECM must see oil pressure prior to starting. This will drop a flag in the ECM.
Pamela & Mike
From your description sounds like the ECM. We had a 95 and the ECM died while parked at home (lucky) about 9 years ago. My coach was parked in a garage so I couldn't get to the back of the engine, it would have taken big truck to drag it out so I replaced the ECM in place, cranked right up. It's not too difficult to remove but exhaust all other options first. ECM isn't cheap. If the ECM is getting power and does not respond when the ignition's turned on that's a pretty strong indicator. The definitive test would be to get someone to try connecting a Cummins diagnostics computer.
When mine died it was obvious it was the ECM, no response when powered up. Engine turned over but no lights or responce from the ECM. If this is the original ECM I'd be very suspicious of it. These early ECM's are more failure prone than later versions.
If you replace the ECM also replace the engine position sensor, doesn't cost much and easy to get to. I bought a Cummins reman ECM and posistion Sensor from:
http://www.heavydutypowertrain.com
I have a new internal wiring harness I purchased for the 95 M11. I had a friend with a 95 M11 that died then restarted on the side of the road, turned out to be the harness. I'd sell the harness for $100, won't fit my ISM. Price is over $300 on http://www.heavydutypowertrain.com
FYI Terry had the ECM programmed for my coach so all I had to do was install and drive.
Thanks for the great replies! The coach has been sitting for almost exactly a month. It ran great all the way up to Alaska with no hesitation or stalling on the whole 3,700 mile trip. Luckily, it has decided to do this while ensconced in a campsite, and not in the wilderness of the Great White North. I have been hunting down sensors and checking connections, but I will look for the cam position sensor this morning. I do fear that the lack of CEL when the ignition is on points to the ECM as Dave states. Does anyone know which/how many contacts should be hot on the round connector going to the ECM? I believe this was used as a firewall connector on truck installations, but is just clipped to the side of the harness on our coaches. After sleeping on it, I realized that the power may be getting through the fuses, but that does not see it safely into the ECM. Wishful thinking...perhaps, but I would feel a bit silly to stuff a fresh ECM in there and not be up and running :( Dave, I may well take you up on that harness, we will see how this goes.
After setting a month in Alaska I would look for some teeth marks in the wire looms causing the electrical impulses to get lost. We are hoping it is something small and not the ECM.
If the round connector you are talking about is grey (or ours is grey) that is where Cummins hooks up there diagnostic computer rather than using the one under the dash. There is a wiring diagram of it somewhere in the archives, I'll look around to see if I can find it.
Pamela & Mike
Thanks Mike,
Please don't let me run you in circles today. I have a very understanding gentleman coming to look at the coach this afternoon,(EDIT: He is not coming to work on it, he is looking to buy it. I call him very understanding, because after he got my Email that it suddenly did not start, he did not call me a flake....I could not have blamed him.) and I will attack this again in the morning. This is our second Foretravel and we have been full-timing for eight years, but we are making this move to Alaska permanent, and not wanting to do winters here in a motorhome. I thought the round plug might be where the ECM drew power, but that is not sounding like the case. By the time I found the fuses and found they were good, it was finally getting dark enough that I gave up on tracing down the wires last night. I was getting pretty hungry too! I will update as soon as I figure something out. I have seen no nests, nor evidence of critters, but I will keep an eye out. Moving up from the dry in AZ, to a lot of moisture and rain on the last two days of our trip, maybe some moisture is somewhere it shouldn't be. If anyone does know pin locations or where exactly this thing pulls power from, that is my next step. I think with time and daylight tomorrow, I will trace down the three fused wires; that should lead me to a pretty good conclusion.
Thanks Again,
Joe
Hi all, started fresh on Saturday morning and pulled the connectors on the ecu. On the "C" plug, I have voltage to pin 20, 21, 22 and 23 at all times. Also to 26 when the key is on. I also have three good grounds in the proper place (cannot recall where now as they are spread out, but I had notes in front of me @ the time). Still no power to the fuel solenoid, nor a CEL. Methinks the ECU is singing with the Choir eternal. I called Terry at HDP (Yup, the man answers his phone on Saturday. He is a real Gent.) He agreed to test mine and he could likely tell me what made it fail. He also said he may have the original 400 horse tune instead of the 375 that most folks end up with.(I saw that discussion on this board somewhere) I intend to replace the fuel solenoid and at least the sensor harness, but I am curious to hear what smoked it. (maybe age, it is the original) Terry will have it Tuesday, so I will likely speak up about it sometime after that.
Thanks All,
JDC