Truck Has Some Issues

[SuiteSuccess]

Was hooking up to start a trip and truck started fine, aired up, then shut down and got these three messages.  Checked battery grounds, recycled key six times, and tried starting.  Ran rough for couple of seconds then shut down.  Any ideas or suggestions?

 

 

[SuiteSuccess]

More to the story.  Went back over to truck and engine, brake, light module all starting with “SAE J 1939 data link communication error.”  Cannot get DID to download faults while trying to do diagnostics.  Any ideas?

[Darryl&Rita]

What did you touch?

[SuiteSuccess]

23 minutes ago, Darryl&Rita said:

What did you touch?

Nothing.  Started truck to hitch up.  It aired up fine.  Idled fine.  Released brake to back up and started running very rough and died.  All three messages popped up.  Checked all grounds at battery.  Went home to think, back to truck and when I turned on key, got the J 1939 message.  Guess I need to check the resistors but not sure I know where or how.

Edited May 22, 2023 by SuiteSuccess

[Darryl&Rita]

It could be corrosion in any of the harness connections, in addition to the resistor. Time to hit the wiring diagrams in the Resource Guide. Good luck. Assuming the batteries are charged and all in good condition.

[SuiteSuccess]

11 minutes ago, Darryl&Rita said:

It could be corrosion in any of the harness connections, in addition to the resistor. Time to hit the wiring diagrams in the Resource Guide. Good luck. Assuming the batteries are charged and all in good condition.

Batteries charged and 6 mos old   Thanks. 

Edited May 22, 2023 by SuiteSuccess

[SuiteSuccess]

Daryl,

Electronics cleaner and q-tips best way?

[Deezl Smoke]

Even though the batteries are near new and charged, I would still consider checking the alternator. A faulty alternator diode pack or even a regulator gone bad, can cause power supply issues to the ecu/ecm and all modules.

Edited May 23, 2023 by Deezl Smoke

[Wrknrvr]

        This could be a simple fix for you. A very slim chance, but it happened to me.

     I had not cleaned my battery terminals for some time. We were in Alabama for a week once, so I had time to clean the terminals. Normal cleaning process and put everything thing back to gather as it should be.

     We left Alabama and headed west. About 75 miles down the road, bad lights came on the dash. Flashing,     And my pulse rate went up. Told the wife we need to get off the interstate ASAP.

    Found a place to pull over.    Was looking at things under the hood, around the batteries and testing voltages. Had two other truckers  just take a quick look. Nothing.

    But then I touched one small wire and it was not really tight. Now I just tightened everything in there just the other day. Apparently it was power to the ecm positive.

   The nut is tight. But the wire is sorta loose. Just how could that be.     Original battery nuts were long and stainless . So I took the nut off and noticed the nut was not threaded the whole way through.  Never seen a nut like that on a battery.     The nut tightened on the top of the battery post.      Not on the wires.

   Found a regular nut. Installed it as should be.

   Problem solved.

   So it could be a simple thing.

 

  As Darryl said, look at what you touched last. 

[SuiteSuccess]

Thanks everyone.  Plan on spending today at the truck.  Will let you know if it’s fruitful.

[Sculptor]

These things are frustrating.  Good thoughts your way.  (Sorry no help tho 🙂)

[Darryl&Rita]

16 hours ago, SuiteSuccess said:

Daryl,

Electronics cleaner and q-tips best way?

Start with just a quick disconnect, look inside, then reconnect. Friction of the removal/reseat can clean off contacts without getting too aggressive. The inspection can identify those needing more attention. In those cases, a toothpick is a better tool than a q-tip. Q-tips are too thick to get into many of the connectors.

[Wrknrvr]

     You can cut the end off a q-tip for a intermediate size tool for cleaning. Also if you cut it at a angle, it can fit more places and in tight spots.

   One time my ecm fuse holder was corroded inside the wire, at the edge of the holder itself. I found it about 10 minutes before a mobile truck mechanic showed up. He was a friend I knew in Florida. I fixed it quickly and had him put his computer on the truck just to make sure it was ok.

 

   I was lucky that day. It acted up about 3 times on my way back to the campground. When I made the last turn on to my street, the engine shut off. Coasted into my parking spot.

 

   Good luck today

[SuiteSuccess]

Ok new wrinkle in the saga.  First took all the connections offf battery, cleaned and made sure all was well.  Took all grounds off ground block on firewall and cleaned, cleaned all weather pak connections I could get to.  This afternoon gonna tackle getting grounds off of starter and cleaning.  Now to the new wrinkle.  My Davco is in the way of the starter but noticed fuel level is below rim of Davco.  Filter was changed last year and was above rim at servicing.  Could that be the culprit?  Sucking air and resulting in the module confusions?  Anyway gonna add some diesel to Davco and see if level stays the same.  I have new caps and o ring already as well as ball valve so can fix 

[rickeieio]

Carl, find your hand primer and pump it.  If it pumps easily, it's sucking air.  Filling the Davco will supply fuel to the hand pump, but that won't fix the issue.

[Sculptor]

6 minutes ago, rickeieio said:

Carl, find your hand primer and pump it.  If it pumps easily, it's sucking air.  Filling the Davco will supply fuel to the hand pump, but that won't fix the issue.

I went through similar fun after replacing fuel filters and separator.  Jack told me 120 pumps minimum. I did that and worked like a charm. Until then it was very easy to pump but only got hard up around 120 or so. 

[rickeieio]

Carl,  silly question, but have you checked your fuel tanks?  if someone borrowed all your fuel, you'd be sucking air.

[Deezl Smoke]

 I believe the Davco runs on filter resistance. Low fuel level means a clean filter. Once the filter begins blocking, the fuel level raises.

 

[SuiteSuccess]

3 hours ago, rickeieio said:

Carl,  silly question, but have you checked your fuel tanks?  if someone borrowed all your fuel, you'd be sucking air.

I have fuel.  Storage area is gated with security cameras.  Never a theft issue so far.  This investigation procedure is time consuming and hard work, but boy it’s fun getting greasy and leaving a little blood here and there.  BTW gonna change check valve in Davco at next filter change.  They can be an issue.

Edited May 24, 2023 by SuiteSuccess

[Darryl&Rita]

3 hours ago, Deezl Smoke said:

 I believe the Davco runs on filter resistance. Low fuel level means a clean filter. Once the filter begins blocking, the fuel level raises.

 

Winner winner, chicken dinner. Get a couple handfuls of road dust into each tank to make that filter work. When the fuel level gets to the top of the filter, it's due for a change.

[SuiteSuccess]

4 hours ago, Sculptor said:

I went through similar fun after replacing fuel filters and separator.  Jack told me 120 pumps minimum. I did that and worked like a charm. Until then it was very easy to pump but only got hard up around 120 or so. 

Mine is priming after 4-5 pumps and becomes hard at that time.

(BTW folks we’re talking mechanical issues so no off color jokes.  Know my friends and acquaintances too well🤪).

[rickeieio]

We have red flags, and red herrings.  The low fuel in the filter is a BIG red flag.  All those messages on the display are herrings.

My money's on the o-ring on the top of the Davco letting in air.  Been there, fought it for weeks.  It took 3-4 days for the filter to drain enough for the motor to suck air.

[GeorgiaHybrid]

The fuel in the Davco on my truck will stay at the bottom of the filter if it is new and start going higher as it gets clogged. I really don't think that is your issue. The J1939 communication fault it is showing is the onboard network that ties all of your modules together and the test port (where you hook up a computer for testing) is the J1939 communications port. It sounds more like a loose/bad connection at a module or a break in a wire somewhere. 

Edited May 24, 2023 by GeorgiaHybrid

[Deezl Smoke]

 A lot of people like to wash their engine compartment and when doing so, especially an engine with some miles on it, accidentally get the water too close to the ecu/ecm connections. It takes very little to cause condensation to appear on the pin connections, and/or get a bit of water by the seal if the connector has been removed a time or two.

 If the power pin at the connector has any corrosion, or oxidation, either from moisture or heat with a slack connection tolerance, that pin can not carry the full voltage needed. No matter how new or clean the batteries, the compromised connection can not carry the volts nor amps needed for the ecm to operate.

 Check vehicle ecu, check brake ecu, and check light module. All at the same time? I dunno, but once you're done with the rest of the connections, I'd almost bet the power pin is'nt carrying proper voltage at the ecm.

[SuiteSuccess]

8 hours ago, Deezl Smoke said:

 A lot of people like to wash their engine compartment and when doing so, especially an engine with some miles on it, accidentally get the water too close to the ecu/ecm connections. It takes very little to cause condensation to appear on the pin connections, and/or get a bit of water by the seal if the connector has been removed a time or two.

 If the power pin at the connector has any corrosion, or oxidation, either from moisture or heat with a slack connection tolerance, that pin can not carry the full voltage needed. No matter how new or clean the batteries, the compromised connection can not carry the volts nor amps needed for the ecm to operate.

 Check vehicle ecu, check brake ecu, and check light module. All at the same time? I dunno, but once you're done with the rest of the connections, I'd almost bet the power pin is'nt carrying proper voltage at the ecm.

Voltage to the ECM has been suggested once before by someone on a phone conversation.  I really don’t have the know how to diagnose that issue so going to try everything else I can safely do myself and then if no success…off to dealer.  One bit of good news (if you call it that), I priced the tow to the dealer and it was quoted half of what I thought it would cost.  Oh well, one or two more days of getting greasy and a little blood then decision time.  Thanks everyone for the help.