Jump to content

Please Help - Intermittent Stalling

rugz31

By rugz31
in Troubleshooting & Recalls

 Share

Recommended Posts

rugz31 Enthusiast

rugz31

Posted
Posted

Hello all,

 

I've been having some issues with my 2014 Silverado randomly stalling on me for the last couple months. Seems to happen more frequently after heating up. At first, it would usually run for 2-3 hours before stalling, but now it seems to be getting more frequent, maybe every 30 minutes to an hour. It will stall while idling or while under load. I've checked 12v battery several times at different places, everyone tells me the battery is good. I've checked cable connections, battery ground, etc and found no issues. I've gone over the fuses and didn't find any that were broken.

I hooked a VCX Nano up to the truck and these were the codes it pulled: U0101 Lost Communication with TCM, U0121 Lost Communication with Electronic Brake Control Module, P0621 Generator L-Terminal Circuit. I attached the DTC log from the VCX Nano if that's any help.
 

Here's the catch: the truck was converted to an aftermarket Plug-in Hybrid by VIA Motors making diagnosis even trickier for me. The truck stalls while running on battery power and on ICE generator. I'm not sure how relevant these codes are to what I'm dealing with. For instance, the U0101 code seems to be irrelevant because the truck doesn't have a TCM or a transmission. I'm leaning toward an electrical short or bad ground somewhere or possibly ECM failure? Does anyone else have any ideas what could be causing my issues?

DTC Display_3GCUKPEH6EG534156_03 05 2021 14 40 14.html

LDM Enthusiast

LDM

Posted
Posted

My 2018 would just randomly die while turning for no apparently reason.  Ended up being the negative battery cable.  After replacing it in the summer of last year I haven't had an issue since.  I know your truck has a lot more going on with the swap but I would start with the grounds and then swap that if it still does it.  Seems like there are a lot of issues with the factory negative battery cables and sensors on the 14-19 trucks.

rugz31 Enthusiast

rugz31

Posted
  • Author
Posted
1 hour ago, Snowcamo said:

I really am interested in a vehicle without a transmission. Can you elaborate on the hybrid swap? 

Sure. So it's essentially been turned into an electric vehicle, it uses electric motors to drive the wheels. The ICE is used as a generator to recharge the HV system. The HV system runs for between 30-50 miles on battery power alone, when the battery drains to about 20% it kicks the ICE generator on to drive the system. It's weird to drive because the engine revs don't match when you put your foot on the gas, it revs when the HV system determines it needs more power. It's pretty strange to drive until you get used to it. I can't give a whole lot of specifics because I'll be honest I don't really understand much of it that well either. I just know the bellhousing, TCM, starter, alternator, and several other parts were removed to add the hybrid drive system.

The chairman of the company who did the conversion, VIA Motors, is Bob Lutz who I'm sure a lot of you are aware of. He did an episode of Jay Leno's garage a couple years ago to showcase the truck. Here's the clip from the show if anyone is interested.
Jay Leno's Garage- VIA VTrux

rugz31 Enthusiast

rugz31

Posted
  • Author
Posted
1 hour ago, LDM said:

My 2018 would just randomly die while turning for no apparently reason.  Ended up being the negative battery cable.  After replacing it in the summer of last year I haven't had an issue since.  I know your truck has a lot more going on with the swap but I would start with the grounds and then swap that if it still does it.  Seems like there are a lot of issues with the factory negative battery cables and sensors on the 14-19 trucks.

I have checked for voltage drop from battery post to the negative cable clamp and there's no drop. Maybe it drops in a different part of the cable? I checked the ground to the block and it seemed good, but I'll give this another look.

I forgot to mention a few other specifics about the stalling. I don't lose power to radio, dash lights, interior lights, etc. The engine just stops running, everything else works fine except heater/AC blow room temperature air (air temp can't be controlled through dash thermostat). One time when this happened, I did have lights on the dash saying "battery saver active" and "battery low- start vehicle." Only one out of probably 20 times it's stalled that I've gotten these messages. The rest of the time, it might give stabilitrak or security messages. When it stalls, it won't start right back up, it has to sit for several minutes or sometimes hours before it will start back up and give me the "ready" signal to drive.

I had thought it was the ignition switch originally because the truck acted like somebody just turned the key off. Changed that but it didn't help.

LDM Enthusiast

LDM

Posted
Posted
50 minutes ago, rugz31 said:

I have checked for voltage drop from battery post to the negative cable clamp and there's no drop. Maybe it drops in a different part of the cable? I checked the ground to the block and it seemed good, but I'll give this another look.

I forgot to mention a few other specifics about the stalling. I don't lose power to radio, dash lights, interior lights, etc. The engine just stops running, everything else works fine except heater/AC blow room temperature air (air temp can't be controlled through dash thermostat). One time when this happened, I did have lights on the dash saying "battery saver active" and "battery low- start vehicle." Only one out of probably 20 times it's stalled that I've gotten these messages. The rest of the time, it might give stabilitrak or security messages. When it stalls, it won't start right back up, it has to sit for several minutes or sometimes hours before it will start back up and give me the "ready" signal to drive.

I had thought it was the ignition switch originally because the truck acted like somebody just turned the key off. Changed that but it didn't help.

I didn't lose any of those things either one mine, the engine would just die out.  It only seemed to happen while turning, which was also strange.  I spent some time cleaning up the grounds and making sure they were all clean and secure.  None of that seemed to help so I ended up just getting the entire negative battery cable assembly.  After that I haven't had a single issue.

 

I know yours is going to be a bit more complicated due to your hybrid setup.  But considering that a negative battery cable assembly is only around $80, I would do that first.  Not sure if it was a bad batch of these or what but I'm not the only one that has done this and had it fix weird issues like this.  I even ohmed out the cable and it didn't show any different than the new cable.  Maybe the sensor was causing the issue?  I'm not really sure.

rugz31 Enthusiast

rugz31

Posted
  • Author
Posted
7 minutes ago, LDM said:

I didn't lose any of those things either one mine, the engine would just die out.  It only seemed to happen while turning, which was also strange.  I spent some time cleaning up the grounds and making sure they were all clean and secure.  None of that seemed to help so I ended up just getting the entire negative battery cable assembly.  After that I haven't had a single issue.

 

I know yours is going to be a bit more complicated due to your hybrid setup.  But considering that a negative battery cable assembly is only around $80, I would do that first.  Not sure if it was a bad batch of these or what but I'm not the only one that has done this and had it fix weird issues like this.  I even ohmed out the cable and it didn't show any different than the new cable.  Maybe the sensor was causing the issue?  I'm not really sure.

That's good to know, thanks for your input! Maybe I'll give that a shot tomorrow. I have a circuit test tool supposed to be delivered tonight so I can check relays and wires and stuff to see if there's a short somewhere. It's supposed to tell me if I have a bad ground as well.

Really have my fingers crossed for a simple fix like negative battery cable. I've been planning on selling the stupid truck after I get it fixed as it's been a huge pain trying to get VIA to help diagnose the problem. Carvana gave me an offer $6.5k higher than I paid for the truck 8 months ago. I got a helluva deal on it at the time, $15k with only 17k miles. I guess people got scared by the hybrid system, and now I completely understand why. I just would hate to sell it when it only has 17k miles on it. If it's such a simple fix, I might reconsider my plan to sell.

rugz31 Enthusiast

rugz31

Posted
  • Author
Posted (edited)

I don't know if this helps at all, but I spent a little more time messing with things on the truck tonight. I let the truck idle in my driveway until it stalled out, approximately 30-45 minutes. When it stalled, I turned the key off for a few seconds and then tried to start it back up. I tried several times, no luck. My next step was I disconnected the battery and touched both cables together for about 30 seconds. I reconnected the battery, and attempted to start the truck. It started immediately. 

I played with this for a few more tries. Let the truck idle, when it stalled I disconnected battery cables and touched them together for 30 seconds. The truck started up immediately every time. While the truck was idling, I tried to keep an eye on the modules through my VCX Nano and GDS2 software. Every time I tried to get into the ECM, the truck stalled. After it stalled, I'd get error messages saying "lost communication with module" or "no communication with module." I'm really thinking my ECM is shot.

 

EDIT: Forgot to mention i had an issue with shifting into park tonight. I moved the truck to a different spot in driveway, tried to put it in park, and the dash indicator started flashing "N" and truck rolled back. For some reason even though I had moved the shift selector up to park, the truck still thought it was in neutral. I had to re-engage the shifter and put it back into park.

Edited by rugz31
rugz31 Enthusiast

rugz31

Posted
  • Author
Posted
12 hours ago, silveradosid said:

have you looked at the freeze frame data to see if there is a specific cause. also being a 2014 i would check the 218 ground connection, was a common problem

I've tried, but I'm honestly not exactly sure what I'm looking at. My cheap scanner shows the DTC associated with stall is U0101 Lost Communication with TCM. Haven't been able to access it on GDS2 but I'll keep trying.

One of the first times the truck stalled, I ripped the dash out on the side of the road to deal with the 218 ground, but it's possible I didn't get enough insulation out. I'll give that another look tomorrow because my original thought was BCM failure. Since I'm having the shift issue, I think that rules out BCM but it's possible the two issues are unrelated.

rugz31 Enthusiast

rugz31

Posted
  • Author
Posted
7 hours ago, silveradosid said:

you want to see the time stamp on when the codes are set. the p0621 code maybe the cause of all of this, i would try and solve it first. https://www.obd-codes.com/p0621

I was wondering about that code as well, a lot of the symptoms line up with what I'm experiencing, but the tech I've been trying to work with from VIA Motors is saying none of the codes are relevant. His thinking is something is causing the shift box to lose signal and causing the shutdown when it doesn't get a response. I've got no idea if he's onto something or if he's completely off, he's been kind of all over the place since I started working with him.

I was able to pull freeze frame data and it shows a new code listed as Failure 1, P2160 Vehicle Speed Sensor 2 Circuit Low Voltage. I have no idea if this is relevant or if this is another symptom I'm wasting time chasing rather than the root cause.

Data Display_NOVIN210309120018_03 09 2021 12 08 49.html

  • 3 years later...
louddakota New Member

louddakota

Posted
Posted

Hi, 

were you able to ever figure anything out with your truck? I also have a Chevy Vtrux 

and my motor will start and it will run like normal, but if I turn it off, it will not restart until the vehicle sits a few hours. When I have a fully charge, the motor doesn’t run the vehicle will drive perfectly under battery power but as soon as the gas motor is needed, I have start stop problems with the motor. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,978
    Total Members
    8,960
    Most Online
    rayredbone
    Newest Member
    rayredbone
    Joined

  • Who's Online   0 Members, 0 Anonymous, 510 Guests (See full list)

    • There are no registered users currently online

  • Latest Articles

  • Posts

    • Grumpy Bear
      AFM Experience

      By Grumpy Bear · Posted

      Question @diyer2 on this line if you please. Are you saying the shudder is the system turning on and off at the frequency of the shudder? Guess I'm asking if you are saying you have seen it do this with the bi-direction scan tool in graph mode? If so have you been able to discern the 'trigger'. Something is telling to cycle rapidly.    My truck just started doing this recently. 197K on the clock. My response has been M5 anything under 55 mph. I treat it like a lugging stick shift. Gear down and let it spin a bit. Engauge M5, then tow mode and then M6 lets the trans stay in 5th but the AFM is active. Smooth like Skippy.    My thought was that as a machine ages the friction gets lower and as the system is load based, the lower friction would allow it to turn on at ever lower rpm until it reaches the lugging point. And yes I am ignorant of any minimum rpm requirement for the system. If you know that would be useful information.    As you know I run a Scan-Gauge II which allows me to watch the On/Off of the signal to the VLOM. While in the shudder mode I'm not seeing is cycle at that frequency or at all for that matter outside the triggers @newdude posted a few years back. Now is it possible that the refresh rate isn't fast enough to catch it? Maybe. It is why I asked my first question about graphing and trigging parameter.     As we have observed from members here the failure point is all over the map miles wise as you note yourself in your opening post. That by itself begs a few questions like fellows that comment on these lifters failing even after the system has been disabled. Long after. 😬   https://www.enginelabs.com/news/tech-tips-replacing-ls-active-fuel-management-lifters-with-melling/   The Gen5 lifters operate the same as the LS versions. In fact they are the same lifter.    https://www.enginelabs.com/tech-stories/sorting-out-gen-v-lt-lifter-failure-with-a-simple-valvetrain-fix/        
    • SwitchBladeSierra
      14-18 Sierra 1500 Heated Steering Wheel Help

      By SwitchBladeSierra · Posted

      UPDATE 2: Steering wheel control backlights and control of the cluster can supposedly be achieved by adding a wire to pin 20 of the cluster and tapping it to pin 2 of the main clock spring harness. I'm going to give it a shot - will update  
    • newdude
      Seems to be Missing a lot of Updates

      By newdude · Posted

      GM Global A pickups 2019-2022 can do OTA programming for the radio.  GM VIP (GM Global B) can do OTAs for almost every module on board.  So a 2022.5 and newer pickup can do OTAs for recalls like the 2.7 fuel flow recall.  EVs get OTAs that improve one pedal driving, radio issues, HVAC issues, updated battery management software, etc.     So age of the vehicle/what GM electrical platform its on will alter what amount of updates can be pushed on OTAs.  
    • Blade8971
      Upgrade to a 2026 AT4 with the 3.0L Duramax

      By Blade8971 · Posted

      Thank You.   So far my new ride is making me look like a genius for going with the 3.0L, as my first fuel refill occurred over three weeks from when I took delivery.  This engine combination is very amazing.  So far no issues and had not done a regen yet.
    • Chuck FB
      Correct way to service 2024 l8t allison trans?

      By Chuck FB · Posted

      I am curious as to how much fluid you put back in the transmission ( assuming you had replaced the filter to compare to my findings ) and then went through the process of warming up the trans before pulling the check plug to drain out the excess and if you measured how much came back out.    I just found it surprising that some claimed a certain amount less fluid being put in and then draining some back out. The attitude of the truck as per if the surface is level and how the trucks stance is would make quite a difference since the check plug is right at the front of the transmission. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...