Wasn't sure where to stick this so I'm putting it here, if the moderators feel it fits better elsewhere they can move it for me. Anyone had any experience with engine ECM's, one of my engine's is causing grief AGAIN and this time it appears to be had, or so I'm told and have figured out by attempting to troubleshoot it, its on a cummins in a truck and has been nothing but grief from day one. Has anyone sent their ECM in to be repaired, and if so, was it worth it, where would you recommend sending it to and what did it cost, and lastly, did they actually stand behind their warranty on it? I've been pricing ECM's from used to rebuilt to aftermarket to new and now I see mine can be sent in to be rebuilt. Anyone with ideas, thoughts or anything else, please post here. Thanks for any replies in advance.
Do Cummins offer through their dealers something like a Reman ECM ..? I've had nothing but bad experience of trying to repair ECM's, either first-hand or any other hand........
Genuine Cummins is the ONLY luck I've ever had with a Cummins ECM. What model engine is it Randy88?
is it an ixs
No advice, just support for your ire! I have 2 cummins isx 485's and they give me nothing but trouble... ECM issues, high crank case pressure, etc, etc. who's responsible for this problem? One truck is parked & the crew actually runs our 2002 T800 Kenworth with a c10 and it never has a problem
I would replace the engine wiring harness first. And if the ECM is in fact the problem a faulty wiring harness probably shorted it out. In my experience if the ECM powers up , about 90 percent of the time there is nothing wrong with the ECM. I have also seen an ECM fix a run ability issue only to have the problem reoccur. The problem in these cases was the connection at the ECM and the terminals connected with one new side worked temporally, or moving the harnesses to replace emc made the connects once again temporally connected. On engines with electronic injectors the wire connection can check good for continuity and still not carry load or transfer pulse width accurately across connections . An example of a recent ECM failure. Engine code something like this . Engine boast pressure sensor open or short to ground. Engine in derate condition. Boost sensor signal wire shows continuity to ground with KOEO . Unplug connector at ECM , no longer continent to ground. ECM failure. The wiring harness with the woven plastics strands will sqeeze the bundle of wires together, add some oil of fuel and the insulation on the individuals wires is softened and can make contact with the other wires in the bundle.
Its the first year of L10 with the computer controls on them, sure wish it was one year older with a mechanical engine in it, all I've ever heard of any brand of electronic engines is they are nothing but grief and expense. I've talked to so many locals, everyone with their own ideas and input, but the consensus seemed to be, the best you could hope for was a year tops without having to redo it again and spend the money again. At that rate, I might as well give up and jerk the engine out, and put a remanufactured mechanical engine in the truck, in the long run it'll be a fraction of the overall cost compared to continuing to fight this problem.
You will be surprised how relatively inexpensive a cummins engine wiring harness is. When I Personally get to the throwing parts stage of it, I start with the least expensive parts, but thats just me.
Check out "strange 5.9 Cummins quirks " in the truck forum below.
What's the truck actually doing? I really haven't seen a whole lot of problems with those L10E's. They're barely electronic compared to today's stuff. Lol.
The truck won't start, has nothing coming out of the ECM but if I was told correctly, we have power going into it, I just put new batteries, cables and a rebuilt starter into it, along with battery boxes and a rebuilt alternator this go around. As for getting to the point of throwing parts at it, I was thinking we've always been at that point, I've had this truck for almost 15 years ish, maybe longer, time flies. I'm thinking we've done the computer and harness once before, maybe more that just once, I'd have to decipher the file on this truck to determine just what's been done to it and when. I've been pricing parts and the whole shotgun approach to fixing it, basically the worst case scenario of what we'd have to stick into it, the problem comes when it exceeds the value of the truck several times over and may not fix it and get it back on the road again, and nobody will guarantee anything. The other problem is, anything electronic can't be returned if we decide to give up mid way through on the problem. As for who's to blame, that's a good question, all brands have their own set of issues, but from where I sit, everyone's standing in line to make a buck off this stuff, its the greatest cash cow ever invented, but that's just my opinion.
I am not there and have no idea what you have been through with this truck, but in an effort to help. The ECM must have two sources of power to power up. Un switched and switched.
Is that one of those Freightliners with the hidden fuses behind the battery box deal I've heard about?
Not sure about the fuses, but the ECM un switched voltage is almost always drawn directly from the batteries.
If this were a caterpillar engine you could do the "bypass harness test". I would assume cummins has the same test available if not in the book I'm sure you could figure out how to bypass your harness to be sure it's not or is the problem...TIO
Yes it has two power sources, both switched and unswitched, I'll have to retest them again when I have time, but I was almost positive we had power to both. No its in a peterbilt, and those fuses are behind the dash, you pull the dash apart and they have a fuse holder bolted to the dash plate once you dig deep enough, both fuses are good, there was some confusion there should have been three out of four panel fuse holder, but there ended up being only two fused. This comes as an argument situation because I could have sworn the last go around, there was also a single fuse holder in the battery box, also the reason I'm thinking off the top of my head, the wiring has been replaced, but we can't find that invoice either. We've been having issues with low voltage to the starter, the reason why the new cables, batteries, and the rebuilt starter, not sure which was the problem, or a combination of all three, but when we put it all together, we solved that issue, now this one came up. There have been all sorts of idea's being spit out, from hooking the wires wrong for the ECM, to accidentally shorting them on something when hooked up, to low voltage killing the computer to a bad spot in the harness that we haven't found yet, the idea of steaming it off before working on may have gotten moisture into something that shouldn't have, to a couple dozen other ideas. Basically tempers were flared and heated over the deal of it not starting so I pulled it out of the shop, and around back to let everyone cool off some before working on it again, there was some discussion of using the truck for a battering toy with a couple dozers so I put everyone in their own corner till I come up with a plan of action for it, not that it was a bad idea, but maybe not the first one I'd prefer to try. That's about all the farther we got when we pulled it out of the shop and around back, I need to bring it back in and do some more testing, just haven't had time and/or been wondering if its worth trying again, or what options I have.
Right, but there should be fuses, fusible links, or circuit breakers in those wires somewhere. Some ECM's I think you have to have ALL the power supply wires in good order or they hit the snooze button on you?
Agreed, but surely it has to go through a fuse or circuit breaker somewhere between the battery and the ECM..?
I've had the discussion of both pete and cummins on the search for the fuses, they both told me it depends on the harness and model of ECM, but according to the book they were both using, the only fuse in the system is in the dash, one fuse could be in the harness in the battery box, but if its not there, some had it some didn't, hence the reason for thinking we replaced the harness. I chatted with them to find out if someone cut it off the end of the cable and by the description I gave them, they told me its original and hadn't been tampered with, with as many people who have worked on or looked at this truck in the past decade or so, anything could have happened. I asked about fuses on the back of the ECM itself and they told me they put them either there or up in the dash, but not both places, no fusible links were ever in this system and to forget about looking for them. We were discussing the exact voltage at the pins on the back of the ECM when I got sidetracked and I'll have to phone them back to ask again. As for the snooze button, I was told its either good or not, nothing in between, but again I'm not sure they weren't trying to sell me a new ECM and the reason I asked here in the first place. The next thing I'm not sure of is, I've been told you can fry the ECM with low voltage or a short? I'd think a short would kick out one of the fuses first, and low voltage shouldn't really hurt I wouldn't think when cranking the starter, most batteries will be down to and under 10 volts, so why would low voltage kill the ECM?? If that were the case, when you tried to start a truck on weak batteries or in the dead of winter when things have more draw, wouldn't you fry the ECM then as well?
I don't know for sure about frying an ECM on low voltage but I do know most of them have a low voltage cutoff programmed in, along with the fuel pressure, timing sensors and rpm sensor, if you don't have voltage, fuel pressure, rotation and a list of other things to make it happy, it just ain't gonna try to fire.
Good idea or bad, you can get them repaired. We had a Freightliner crew truck with a Cat in it. It quit and we narrowed it down to the ECM. There is a place I think in Texas that fixes them. Don`t ask me the name of them, phone number or anything ele as I don`t remember it, but I do remember the cost was about 1/3 new and we were selling the truck anyhow. It ran fine when we put it back in and the new owner drove it off.
Not sure yet if this is somehow related, but the last I looked it, was about a week ago, hit the key this morning just to make sure it was still not going to start and now the new batteries are stone dead. We had this issue a couple years ago, nobody ever quite figured it out then either, it just kind of stopped doing it, as stupid as that sounds. Boy the idea of someone else driving it away under its own power sure sounds great about now..............and its insured and everything. Oh well enough dreaming of what will never happen, back to reality and my current problems. I'll make a couple dozen calls and do some more testing and let you guys know about what I did or didn't find out before the weekend comes along.
First thing I'd do is unplug the harnesses at the back of the ECM. Check for power at the correct pins coming out of the harness. (I can probably find out what pins if you get me a serial number). I always make sure the ECM has everything it needs to be operational before throwing one at it. You can have power at the fuses and still no power at the ECM if you've got a rubbed wire. Does the check engine or stop engine light come on when you turn the key on?
I've been working on it all day, haven't accomplished much if anything, been on the phone more than not calling and asking anyone I can think of, both cummins and pete claim there is nothing between the batteries and ECM, I have power from the batteries to the first connection on the side of the engine, but lose it somewhere between there and the cab fuses. The wiring diagram I have only has the cab portion, nothing engine related is included, both pete and cummins have tried to send me the diagrams and they are completely illegible, they couldn't even read them to tell me what to look for or where. The engine serial number is 34648536 according to pete, the serial number on the engine itself is illegible, the last of the truck vin is 312882, if anyone has a legible diagram for a L10e cummins, I'd appreciate it. We've pulled the plug out of the ECM and we have nothing now for power there at all. Its possible the harness is rubbed through, but I'm thinking there has to a circuit breaker, in the wire from the battery to the fuse for the ECM, but I certainly can't find it if there is one, I have yet to take the dash completely apart looking, but its about to that point. As for a rubbed wire, that was the problem this morning down by the starter, a wire had rubbed the coating off against another ground wire and was a direct short, took some looking but I finally found it and figured out what happened, some new ends on the wires and that was cured. As for at the plug on back of the ECM, I have nothing there at all on any of the power terminals, which is the reason I'm thinking a breaker is tripped somewhere, the main cab breaker is fine, and I don't think that ECM circuit should go anywhere through that, but I am curious as to why they didn't take the power for the ECM off the cab breaker, would have saved a lot of hassle going up the back of the engine and through the entire harness to get the power to the cab fuses for it and then back out again to the ECM.
It sounds to me like it would run, then you worked on the starter wiring and now it won't????? If that's the case you need to look carefully at what's connected to the batteries and starter and how, maybe the hot lead comes off the starter for the ECM and somebody accidentally got it hooked to the ground stud instead of the positive? Something along those lines. Just a thought.
Lantraxco, That's what we've been thinking, same as everyone else, but we've checked and rechecked it many times, tracked the wires all down that lead to the starter and everything is hooked correctly, grounds go to the frame and engine and the hot wire for the cab circuit breaker go to the breaker, the starter switch wires go to where they should and the main frame wires are hooked hot as well, we've got them all to where the wiring diagrams say as well as what pete's reps tell me, they also claimed nothing that feeds the ECM comes off the starter anyhow, that comes directly from the battery. The connection we have tested for the ECM runs up above the starter on the back of the engine, just above the starter is where we tested those wires, they are hot there, then feed into the harness and are entwined in the wad of wires that go to the cab connection. My first thought is still the same, despite what everyone says, I think there is a circuit breaker or fuse block in the cab somewhere that maybe someone added and when the starter was taken off, the batteries unhooked and removed, or the wires unhooked, someone shorted them and tripped the breaker or blew the fuse I have yet to find. To me this is the only thing that makes sense to explain what I'm not finding so far, I didn't take this apart and I have no idea how they did it, or what they may have omitted telling me or didn't notice as they did it, which really doesn't matter now anyhow. I've been thinking about this during the night, the only thing I can think to try is to do a continuity test of the harness at the cab connection and carefully cut the harness covering to trace wires up to the cab. Then take the dash apart to access the harness in the cab and stick someone really small under the dash to hopefully find whatever it is I can't see. Cummins wants about 4k for the ECM and Pete wants about 1200 bucks for each half of the harness. I just can't believe since it ran before anything was done, the wires went bad or somehow got cut up behind the engine beyond where I tested them which is out of reach of anyone or anything, its got to be either GFS [green fuzzy sh@t] or a circuit tripped. Once we get power back going to the ECM, we can start to troubleshoot that next. I know I shouldn't be down on technology, and relive the glory years of day's gone by, but this is total BS, how much simpler things were when all you had to do was make sure it had fuel and good batteries in it, and a simple starter circuit to start it or jump it with a screw driver, an alternator to change the system and off we went. Makes me want to just go out and buy a much newer truck with an even more complicated electrical system on them to make my life easier, nicer far better reliability and to ease trouble shooting of problems, oh yea, and to make it cheaper to repair when things go wrong.
I'm having the same problem with my Kenworth T800 with a Detroit 60 series. Wiring and ecm problems. Sending the ecm out to a shop to get it tested for $60.00. Maybe you can do the same to verify the ecm is good or bad?
PNECAT, Where are you sending yours to have checked out. The only thing I found this morning is, nothing of what I've been told is the case at all, we cut away the wiring harness and the wires coming from the battery box don't go to the cab first, they go the ECM first. I'll have to wait till Monday and call cummins with the model and serial number to the ECM and see if I can get a wiring diagram for it.
Okay, just for clarification, you've traced the positive wires from the battery box all the way to the ECM connector? Do they have power or not? If not, where are the fuses, there HAS to be some kind of protection between the batteries and the ECM, possibly inline behind the battery box, along the frame, etc.?
Lantraxco, I took the harness from the batteries to the ECM out from inside the frame and out of the battery box, pulled it completely out and laid it out around the cab and re hooked it to the batteries, there is no fuse's in that section at all, no fusible link, nothing. I pulled the wires and unhooked the clamps/harness from the engine, I may have to pull the starter and ECM box off the truck, so I can see, right now I'm using an inspection mirror to follow the wires up to the ECM box, but I'm about sure they go to the box, not the cab, the other harness goes to the cab. It was dinner time so I haven't gotten back out there to test and finish following the wires up to the ECM or test it at the ECM. I made a few calls yet this morning to ask *** and all I was told one explanation is, someone cut the fuse's off the battery box end, as of yet, I don't know, another explanation is there also may be a circuit breaker in line that would be under/behind the ECM I can't see with the inspection mirror as of yet, I don't know for sure, I have a couple hours left to get everything exposed so I don't need a mirror to see with. Once the ECM is out, and I can get around back behind the engine to follow the wires into the head for the injectors and verify there is nothing around the corner, I don't feel anything by hand, but I want more verification nothing is behind the engine or bolted to the back of the ECM box and bracket somewhere I can't feel or see yet.
Sounds right, patiently following the electrical flow can be maddening on a modern vehicle, but sooner or later you should be able to confirm a fault or eliminate all but one or two possibilities. What you're doing is logical and methodical as opposed to the usual shotgun process. :usa
You're headed the right direction now. Alot of Cummins had I line fuses hidden or tied up to the harness near the ECM. IF you are able to verify 2 wires going from the batteries to the ECM and you still have no power at the harness plug, cut them off about 6 inches from the plug, hook some jumper wires to it and check for power again. If still no power it's about gotta be in the plug. I know it's frustrating but don't over complicate it. ECM'S are bean counters, that's it.
Or better still, invest in a test lead kit for your multimeter with the "hypodermic needle-type" tips in it that allow you to measure for voltage or continuity through the insulation of the wires without having to cut anything. Fluke do a kit, it''s their reference TL81A and it''s saved my ass on a number of occasions. If you now have the harness off and all connectors are accessible would there be any benefit in doing a continuity test in each & every wire to see if you have a case of electrons going in at one end but not coming out of the other..?
I couldn't sleep so I went out to work on it again, finally came up with fuse's after tracking the harness far enough and doing enough testing, they were hid, someone bolted them to the backside of the mounting plate for the ECM, had to remove almost everything to get at them and they were blown, changed them and started sticking stuff back into place enough to see if it started, which it did, I'm not saying its fixed, still have to put it completely back together again and run it some to see if everything performs like it should, but it started and ran which left me speechless. I guess if the starter was out and you'd look just right with an inspection mirror, you could see them....................who in the world came up with putting fuse's there, you wouldn't have been able to change them without removing everything though. I now have to figure out how to bolt them somewhere we can get at or tie them somewhere handy, they are each on a pigtail end about six inches long that came out of the harness on the backside of the ECM bracket I couldn't see or feel, it wasn't until I started testing and taking the harness apart I found them. Thanks for all the input everyone put into this project on my behalf I really appreciate it.
Glad to hear it appears as though you were on the right track. I couldn't for a minute believe that the unswitched supply from the battery to the ECM would not pass through a fuse or circuit breaker first.
There seems to be no rhyme or reason for the placement of the ECM fuses esp with a Cummins. Once on a feller buncher that the alternator was not charging, after customer kept bringing alternators back claiming they were no good, I found the exciter wire to be the problem . I found a diode burnt out. Problem was it was inside the wrap of the wiring harness, I had to actually split the harness open with a razor knife to access and replace. Of course this diode only came with the wiring harness, but I installed a diode from a allied skidder. I then advised customer to replace harness as they are relatively inexpensive . He said he did not care as long as it was working.
I'm going to put my swami hat on and guess someone accidentally reversed the battery cables or jumper cables and took out the fuses, not that it matters much at this point. The evil conspiracy theory side of my brain tells me that's a great place for those fuses if you want to sell ECM's, and you can clean and resell the ECM you pull off to replace the fuses. Follow the money. Well done! :drinkup
Swami hat, that's a hoot, I have no doubt your right, but since I didn't take it apart, I can only guess and wonder..............but just like kids, nobody knows a thing about that, funny how that works. Actually I'm speechless I figured it out, I never gave myself a ghost of a chance to ever troubleshoot anything computer or electrical related, to me those subjects are about like women, I'm pretty sure no matter what I do, say or try, I'm still clueless as to what exactly the signs are telling me, even when they talk and tell me what they want and mean, I can usually manage to botch something and someone ends up mad.
We disconnect the ECU terminal, the 12v power supply wires get probed by a simple harness.... 2 1156 taillight bulbs.. And the other end has a clip to connect to ground. If there's 12 v there with only one or 2 strands holding, it may show good continuity on meter, but the bulbs won't light very bright and then you'll know there's a problem with harness. Same with ground wire, except connect it to power to test if ground is intact. Just be sure you have the right circuits, or you could fry something
Lol... If that applied to me, I wouldn't be able to talk, ever... Seriously, though... an exceptional bit of troubleshooting... Excellent! Yup... Been there, done that too... And why, why, wouldn't it be at, or as close to, the battery as possible? Really makes no sense to me... Again... good job, Randy... :thumbsup OCR
Had a similar issue on a customers 379... It turned out to be rotten connectors on the breakers (on that truck) fuses on yours, they would pass enough current to light up a test light, but not enough to actually work. Took me a while to figure it out. Its been mentioned too, and I'll second that cummins genuine ECMs, harness or harness sections are not that painful to your wallet in my opinion. Just sharing my experience.