Network Issues - Intermittent

Keith Browning · December 21, 2013

Have a 2011 6.7L equipped truck towed in that would not crank, every warning light and message lit up and had a handful of network Communication DTC's in just about every module. All modules involved are on the HS-CAN network. I started diagnostics with the Oscilloscope and wasted a lot of time with my IDS crashing and manually entering the vehicle then trying to familiarize myself with using the scope again and what I was looking at by sampling a known good truck. Long story short I had to take care of some other trucks and the truck sat in the shop overnight and "fixed itself" which usually suggests a wiring concern but I have no data to go on with the scope and I cannot trust the codes because somebody got to the truck before me and disconnected stuff.

At this point I was able to start a new IDS session and properly ID the vehicle, cleared all codes, road tested and performed a self test on all modules and of course all passed. It's a matter of time before the fault repeats and I can re-scope the HS-CAN network and figure it out...

Anyone find anything crazy with these yet?

Matt Saunoras · December 21, 2013

Not on a super duty but I had a 13 Escape that was doing something very similar (if not the same). It was so intermittent that I never could duplicate it with any regularity and the vehicle ended up being bought back.

Brad Clayton · December 21, 2013

Put a carburetor on it.

mchan68 · December 22, 2013

In answer to your question, yes I do. This sounds EXACTLY like one I had towed into me a while back. I couldn't communicate with IDS. After ohming pins #6 and #14 and getting 120 ohms, confirming there was a module offline, it turned out to be a green deathed network wire under the driver's door opening scuff plate. THAT, took a lot of my time to pinpoint. Something else you need to be aware of, is if this vehicle doesn't have the factory trailer brake control option, the connector to it is still present and plugged into the blank plastic trim piece. In that connector is also the HS CAN + and HS CAN - circuits dead ended into it. I also had an issue a long while back where an aftermarket installer had installed an aftermarket trailer brake controller into this circuit by snipping the wires off this connector cutting off the SJB out of the equation in the process, and in turn causing a no-crank no-start that had to be towed into me.

Alex Bruene · December 22, 2013

I've had a few 6.7s with communication issues... I've seen the one Mike is talking about under the driver's sill plate. Most recently, I had a bucket truck that was towed in to me a few times, but every time it was towed in, it would start. I finally went to the fleet location when that truck wasn't starting. The PCM, TCM, NOx and GPCM modules were offline. I wiggled a bunch of shit, and it finally started when I wiggled the connector under the degas bottle... Can't remember the number. I got the truck to the shop, disconnected, cleaned and made sure the pin fit was okay, and opened up the harness to make sure nothing else was going on. The next day, it didn't start again. I eventually overlayed the network circuits around that connector and it has been fine since. I hope.

Alex Bruene · December 22, 2013

Oh, and if I recall correctly... The one with the issue under the sill plate didn't communicate with the RCM... The one with the connector issue did.

Keith Browning · December 23, 2013

In answer to your question, yes I do. This sounds EXACTLY like one I had towed into me a while back. I couldn't communicate with IDS. After ohming pins #6 and #14 and getting 120 ohms, confirming there was a module offline, it turned out to be a green deathed network wire under the driver's door opening scuff plate. THAT, took a lot of my time to pinpoint.

BINGO!

:rockon:Thank you Mike. First thing this morning I pulled off the sill trim and then the kick panel trim on the left side. There are two legs of the HS-CAN network in that part of the harness. I found the white wire Circuit# VDB05 (HS-CAN -) just rubbed through on the bottom of the trim. Add a little dirt build-up, a lot of moisture and ice melting rock salt and you have a path to ground.

Brad Clayton · December 23, 2013

Dang it, I ain't never gonna be able to get rid of this variable venturi carburetor.

Keith Browning · December 23, 2013

And - I am pretty sure I have oscilloscope screenshots of every possible network failure type to make us our own full color job aid. The WSM and training material have small black and white pics. Aside from that I opened up the time scale a litte to show more detail in the network signals.

lmorris · December 9, 2015

So...any other issues you guys have run into? I have a fleet customers truck that complained of IC shutting down, when they shut the truck off it wouldn't restart. Let sit for about an hour and it was good. They took to a dealer close to where the truck broke down and they "diagnosed a communication network fault" and quoted 3 hours to locate and repair it. The truck came here instead. I am unable to verify the concern, and any codes in memory are useless due to the previous diagnosis. I checked the entire engine bay harness and found no rub points, checked the usuall drivers door sill plate, opened up the harness, nothing visual, ran the network test and shook the crap out the harness in every place I could get it to move, nothing....Thinking terminal fretting at one of the many harness connectors between the IC and the PCM as they have all been apart now and reconnected. Stumped. Thoughts?

Fredsvt · December 9, 2015

Not sure if it helps, just had a 2010 E (gas) 181k, that the driver complained of IC and radio going off, for about 2-3 minutes at a time, then back on. If he shut it off, it did restart however.

I took a look, and every time the engine was revved over 2500 the cluster shut down as did the radio.

Just prior to the shut down, the battery light dimly flashed.

Checking charging, 16v at idle, hitting 2500 was just crossing 18v, at 18.5 to 19, cluster shut down. Over 3000 it was well over 22v.

New alternator took care of the cluster/radio issue.

On your truck, any aftermarket modules added to network. Seen major issues in E mobility vans with wheel chair modules causing no starts, no shift (interlock stuck), and other strange issues. Unplugged the module from DLC jumper they use, problems ceased. Seen many with issues when inside of van is cold.

Matt Saunoras · December 10, 2015

The other guy who works with me spent days on a loss of HS-CAN somewhere in a newer 13-14ish super duty, I never did hear exactly what he found but I believe it was an inline connector under the dash somewhere that he reseated and everything was fine after that.

cbriggs · December 10, 2015

I just had a 2015 with 7000km towed in on Monday, 2 months in service. No crank, multiple warnings on the IC. I had no comm with pcm, pcm and NOX 1-2 failed network test. Network resistance was always 60 ohms. Unplugging nox 1-2 made no change. Load tested all powers and grounds at pcm, all good. After reconnecting pcm "b" connector the truck started and ran, then wouldn't restart after shutting off. Disconnect and reconnect Pcm "b" connector, started right up again. The interesting thing is, there are several modules on HS can 2 network, which is not wired to the dlc, and only accessible to the ids through the pcm. all but 1 of these passed the network test. Based on that I was fairly sure the network was intact to the pcm, so either something was shorted out and pulling the pcm down, or the pcm was junk. I went through the hotline reports on the self help tool and found a lot of these are being repaired with pcm's. Also Edmonton depot had a bunch of pcms, which is strange, usually pcm's are usa stock. I hung a pcm in it this morning, and it survived a test drive and retest. Hopefully that has got it, but I may never know as it was not a local customer.