ECM CAN Communication Errors

Hey y'all,

I'm a relatively new T1N owner and Sprinter-Forum user. The wealth of info here has already helped substantially. Thank you! I'm no search guru, but I did poke around and was unable to find a thread documenting a similar experience, hopefully this post isn't rehashing a known issue...feel free to point me to it if I'm wrong (a likely scenario!). Anyway, let's get down to it!

Our van is a 2002 3500 just shy of 110k miles. We recently did some routine maintenance type things, oil/filter change, trans fluid/filter change, brake pads/rotors. We've put about 5k on it since buying the vehicle a few months ago. Usage consists of driving up to 500 or so miles at a time every other week, mixed highway/city and the very occasional gravel road or mountain pass. I typically keep it at or under 70 mph on the highway. When we take it out we are "loaded up" with a couple hundred pounds of bikes and gear, our "build out" consists of a sleeping platform and a bench seat. I'd hazard a guess you all would call this light use. Hopefully that sums up the vehicle information. Now onto the issue.

About 3 weeks ago we had a "long drive" from Atlanta to DC where we spent the weekend racing bikes. Started it up to leave and it quickly died after running for only a second or two. Cranked it over for 30 seconds at a time about 12 times with no start. Battery was charged and both terminals had tight connections. All of the fuses under the steering wheel were good. Had it towed to a diesel shop and they read some codes saying the ECM wasn't communicating with other modules. They determined a ground was bad and that a fuse had popped. Shortly after we were on our way back to Atlanta and over the past couple weeks we made a number of small trips around town successfully with no negative symptoms.

A few days ago I hopped in the van and started it up only to experience something very similar. It started up, ran for only a second or two and didn't start after prolonged cranking. Battery had 12.4v, tight terminals, and all fuses under the steering wheel in tact. I bought an Autel MD808 Pro in hopes to be better prepared for this situation and it gave me very similar sounding errors:

C1022 - The CAN communication of the engine control module is faulty
P2311 - No CAN message from engine control module or message faulty
B1040-000 The CAN communication of the engine control module is faulty

These make me think it is a very similar issue. It should be noted there is an aftermarket trailer brake controller installed by the previous owner, I wonder if how they wired it in is making things behave in a funky way...anywho, it seems I should be checking any and all grounding points of the ECM. It does seem there are a few connectors that plug into that module, so I would think there is more than one ground (feel free to educate me on this, as I am mostly ignorant here). I'm hoping someone can point me in the direction of a wiring diagram or share some knowledge before I start poking and prodding. I'd hate to make the situation worse but I'm also trying to avoid another tow to a technician, at least before giving it an honest look and effort at resolving the issue.

Luckily this time the van is in my driveway which gives me a little bit of time before pulling the trigger on calling in the professionals. Any help you all can provide would be greatly appreciated!

-Zach
 
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billintomahawk

Guest
A couple of things with the '02.
Have you changed the fuel filter recently and do you know about the related air in the fuel line problem that can cause hard starting?
Do you have air bubbles in the clear plastic fuel line between the fuel filter and the low pressure fuel pump?

Secondly, do you know about the possible wear spot in the wiring harness where it is lashed to the support under the fuel filter. If you wear into the harness all kinds of strange things could happen. There are many threads on these two issues.

Thirdly are your tail lights working properly? Sounds crazy but this can also cause all kinds of problems with your machine.

Fourthly crawl under and look for any rodent wiring loom damage front to back.

These are all problems I had and staring was affected.

FWIW

bill in tomahawk
 
A couple of things with the '02.
Have you changed the fuel filter recently and do you know about the related air in the fuel line problem that can cause hard starting?
Do you have air bubbles in the clear plastic fuel line between the fuel filter and the low pressure fuel pump?

Secondly, do you know about the possible wear spot in the wiring harness where it is lashed to the support under the fuel filter. If you wear into the harness all kinds of strange things could happen. There are many threads on these two issues.

Thirdly are your tail lights working properly? Sounds crazy but this can also cause all kinds of problems with your machine.

Fourthly crawl under and look for any rodent wiring loom damage front to back.

These are all problems I had and staring was affected.

FWIW

bill in tomahawk
Thank you for the reply.

The fuel filter was replaced by the shop that diagnosed the no start problem a few weeks back (I happened to have one on hand and asked that they replace after troubleshooting the van, I forgot to mention that in in the blurb about recent maintenance). I'll take a look at the clear fuel lines to see if I can spot bubbles.

I was not aware of the the problems that can arise from the wiring harness rubbing underneath the fuel filter. I'll check that out promptly.

My taillights were being funky when I first got it, replacing the brake switch behind the brake pedal does seem to have resolved it though.

That is a solid suggestion. I'll add it to my investigation tomorrow.

Much appreciated, thank you Bill in Tomahawk!
 
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Nautamaran

2004 140” HRC 2500 (Crewed)
Have a look here:
http://diysprinter.co.uk/reference/

and specifically here:
http://diysprinter.co.uk/reference/2004-VA-SM.pdf
(named 2004, but I’ve found that many of the pages still relate to 2002-2003 models, including ground locations...)

Your plan to visit the grounds would be my first choice too.
There is a lug under the dash hump, two on the floor under the seat, and several under the hood including the main one on the firewall, behind the headlamps on the inner fenders, and the braided strap at the driver’s side engine mount. As a rule, following brown wires will lead the way to these lugs.

Take the nut off the ground stud, wire-brush ALL the flat surfaces of the wire-eyes and the bolt down to shiny metal, reassemble, then give the stack a squirt of battery terminal sealant wax. Even if a ground is not your immediate problem, this is a good investment of time against future troubleshooting - you’ll know your grounds are solid.

I’d also follow Bill’s advice and inspect the main harness where it passes under the fuel filter. This is a known trouble point, and can generate a variety of sensor and communications problems. Cut the zip ties loose, unwrap the covering, and comb through the wires within. Cracks or abrasions to the insulation can be taped or brushed with liquid tape as necessary.

The ECM communicates with at least four other modules over the CANBUS, and has a dozen or so sensors and actuators on the engine that it monitors and manages, so wiring faults can quickly bring you to a standstill... and unfortunately electrons don’t leave puddles when they leak out.

Good luck,

-dave
 

NBB

Well-known member
Resistance between any 2 CAN wires anywhere in the system should be 120 ohm, and neither wire shorted to power or ground - ie, high impedance to power or ground. Check that first. If it looks good, then realize CAN is differential, so I believe ground is only relevant if there is a dead module or sensor somewhere, it does not necessarily indicate a problem with the bus itself - ie, per the above posts - you're chasing a module that isn't powering on and communicating. With a wiring diagram, one would want to locate those one by one and check a power pin. Or better - you have a scanner.
 
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Im thinking its the o-rings on the fuel pressure regulator on the back of the engine.. not a hard fix and cheap. Mine did similar things as yours. There are several threads on this 02-03 only
 
Allso check all of the electrical plugs on the injectors under the cover. i had one not making a good connection. It would do something similar as well
 

Midwestdrifter

Engineer In Residence
In addition to the suggested offered above, do you ever get a start error message on the cluster? Does the van ever fail to crank when you turn the key?

The fuse block under the steering column, known as fuse block one (FB1). Is a known trouble point which can cause the symptoms above. There is a relay on the bottom of FB1 which feeds power to the ECM, and its socket can deteriorate. Typically it does not cause stalling first, but instead causes starting issues.

I agree that a poor ground could cause your symptoms, though you should see others first. Check the ground strap at the engine, and the battery ground strap. Remove the bolt and clean if there is any sign of corrosion.
 
Resistance between any 2 CAN wires anywhere in the system should be 120 ohm, and neither wire shorted to power or ground - ie, high impedance to power or ground. Check that first. If it looks good, then realize CAN is differential, so I believe ground is only relevant if there is a dead module or sensor somewhere, it does not necessarily indicate a problem with the bus itself - ie, per the above posts - you're chasing a module that isn't powering on and communicating. With a wiring diagram, one would want to locate those one by one and check a power pin. Or better - you have a scanner.
Thank you, one of the links shared looks like a manual. There is likely a wiring diagram in there somewhere. My multimeter is also at the go, I'll be checking for 120 ohms of resistance. Crossing my fingers it isn't a dead module!

Im thinking its the o-rings on the fuel pressure regulator on the back of the engine.. not a hard fix and cheap. Mine did similar things as yours. There are several threads on this 02-03 only
Definitely get the different filter from million mile sprinter as well
Allso check all of the electrical plugs on the injectors under the cover. i had one not making a good connection. It would do something similar as well
Nice, those sound easy enough to check. I wish I had known about the fuel filter with less holes from MMS before I purchased and had a replacement intalled, haha, that's how it goes sometimes. Added to the list, thank you much for the responses!

In addition to the suggested offered above, do you ever get a start error message on the cluster? Does the van ever fail to crank when you turn the key?

The fuse block under the steering column, known as fuse block one (FB1). Is a known trouble point which can cause the symptoms above. There is a relay on the bottom of FB1 which feeds power to the ECM, and its socket can deteriorate. Typically it does not cause stalling first, but instead causes starting issues.

I agree that a poor ground could cause your symptoms, though you should see others first. Check the ground strap at the engine, and the battery ground strap. Remove the bolt and clean if there is any sign of corrosion.
I don't get a start error message on the cluster and it is cranking every time. I do recall a difference in behavior between the previous non start event and the current, now that I'm thinking about it more. While broken in DC, after many repeated attempts to start I saw the cluster flicker and flash. I stopped attempting to start shortly after. It hasn't done that this time, but I have only tried cranking it 3 separate times and for much shorter duration.

Ok, I'll add that onto the list to check. I should be able to work out how to test the relay with a multimeter.

Ah yes, the engine ground strap is a crucial bit. From the looks of it I may need a couple more socket extensions! Thank you for your suggestions!



I'm off to get a quick bike ride in, it is the weekend after all. I'll pick up some liquid electrical tape and contact cleaner for cleaning grounds. These replies have been helpful, thank you again y'all!
 
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220629

Well-known member
Check this

Million Mile Sprinter.com

https://www.youtube.com/watch?v=yk8wg8P0y58

bill
"Still has a space for the water". There may be a space, but there is no separating membrane.

I checked with the manufacturer for the MAHLE KL 313 fuel filter which is used on many MB V6 diesel engines. The filters that don't have a WIF warning and drain capability don't have any water separation technology included in the design.

The space at the bottom of the filter housings may work as a catch space for heavy debris, but it is not there to catch and retain water.

The MAHLE KL 313 or equivalent is also an "air leak free" filter. The only openings are the fuel inlet and outlet.

:2cents: vic
 
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billintomahawk

Guest
Baldwin BF7756 will work as well.
Two openings.

8Track, fill the new filter with clean fuel if you change it. The system will re-prime itself after 3-4 cycles using the starter if everything else is correct.

bill
 
Quick update for y'all. I went through all of the grounds and made them shiny. I also pulled the fuse box and am going to clean the contacts on the ECM relay socket as well as test the ECM relay. Next up will be looking at the loom under the fuel filter for any shorts or damaged wiring. Should those not reveal the issue I'll start testing the CAN-bus wiring for shorts.
 

calbiker

Well-known member
Have you deleted the error codes? If yes, do they come right back?

Do you get any data from the scanner? Live data streams?
 
CAN communication errors can often be caused by power supply issues to the modules in question. So take that into account.
Thank you Midwestdrifter.

Have you deleted the error codes? If yes, do they come right back?

Do you get any data from the scanner? Live data streams?
I did delete them. I cranked it over for about 20 seconds with no start then scanned for codes. It didn't come back with all of the same codes, but I did see at least one ECM communication code. Additionally now there is an exclamation inside a triangle on the center of the cluster where the speedometer is, sorta flashes, doesn't stay lit. I assume that is a start error light? I haven't tried to do a live data stream, I am a newbie with this scanner!

I wanted to check before diving into this section of wiring. It was suggested this is a common problem area by a couple other users. The section of loom in question is inside a protective plastic conduit. I'm wondering how other users have sealed that back up.
 

Attachments

99sport

Well-known member
Thank you Midwestdrifter.



I did delete them. I cranked it over for about 20 seconds with no start then scanned for codes. It didn't come back with all of the same codes, but I did see at least one ECM communication code. Additionally now there is an exclamation inside a triangle on the center of the cluster where the speedometer is, sorta flashes, doesn't stay lit. I assume that is a start error light? I haven't tried to do a live data stream, I am a newbie with this scanner!

I wanted to check before diving into this section of wiring. It was suggested this is a common problem area by a couple other users. The section of loom in question is inside a protective plastic conduit. I'm wondering how other users have sealed that back up.
The triangle in the center of the dash is for the ESP / ASR (stability control) module. Mine comes on when one of the wheels is spinning and the computer intervenes to prevent a spin.

The "start error" message is due due to a mismatch in the SKREEM and key chip and ECU (or, typically, no signal from the SKREEM module - plugged into the back of the instrument cluster). If you had a "start error" you would see the words "start error" spelled out in the odometer - not the triangle.

As it sounds like you may have a CANbus communication issue, I suggest you watch this excellent, but rather long, CANbus explanation: https://www.youtube.com/watch?v=uKnQI2IScPU
 

Midwestdrifter

Engineer In Residence
The triangle light typically means an ESP error. I would scan the cluster, ECM, TCM, and ESP/ABS module separately. See which ones come up with codes. If you are able to access all of them, then they are at least getting some power. If you cannot access one of them, it means a module or power supply issue.

Since the engine cranks, that means that the ECM and SKREEM are able to talk over CANbus, and that they have power. I suspect a canbus issue ins't causing the no start (though it could be a related symptom). When cranking, does the tach rise above zero?

With the scanner connected, monitor fuel rail pressure in the ECM, does it get over 2500psi? Depending on the scanner, you may be able to check cam/crank sensor synchronization. No cam sensor signal will prevent fuel from being injected.
 
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billintomahawk

Guest
Thank you Midwestdrifter.

I wanted to check before diving into this section of wiring. It was suggested this is a common problem area by a couple other users. The section of loom in question is inside a protective plastic conduit. I'm wondering how other users have sealed that back up.
The loom on the left(I think) runs under the fuel filter support. If you cut the zip ties free you will see a shiny spot where it has been rubbing. Hopefully that is all you will see, not a worn through spot.

Wrap it there with? I used Gorilla tape with zip ties so it wouldn't unwrap. Not sure if I re-tied the loom tight to something solid, I don't think so.

bill
 
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