Brandonb0013

https://www.gm-trucks.com/forums/topic/248499-30-duramax-cranks-but-won’t-start/page/31/

For what it's worth, I've had this happen now twice in the last three weeks. The last time I had to get it towed, the first time it eventually started after an hour or so. Regardless, the dealership first said it was the alternator (they replaced), that didn't fix it. Then two days after this the Service 4WD popped up, I brought it back in, they found a loose ground cable (G132). Tightened and it fixed it. Fast forward to a week ago and wouldnt start, same issue as described in the original post as well as the first time it wouldn't start. This time at a different service center they found the same G132 cable had a "broken bracket" on the engine side of the cable. There is a techlink article here that was created in December 2019 (before the 3.0L was widely available), that states the loose ground cable problem as well as the affected vehicles (not the 3.0 because not known at the time I'm sure). Also attached are images the last service center sent me. Here is a google photos link showing what is happening at the DIC when not starting. I plan to fix these cable ends in place "permanently" one way or anther... a44daab6-e9dd-46d2-af66-d9b3740649db.jfif 02145852-99cc-4ea6-b495-bdcd3514efb6.jfif

I'd probably have the dealer replace your anbient air temp sensor if that's the case. Apparently that sensor does more than just tell you the outside temp. Sent from my Pixel 4 XL using Tapatalk

Awesome! I'm up in De Pere.

This is interesting. What was the outside temperature when you started the truck? I'm guessing it was below freezing? Also, your icon next to your name is the green G. Are you also located in wi or just a fan? I'm actually in the greater GB area. Sent from my Pixel 4 XL using Tapatalk

This is interesting. What was the outside temperature when you started the truck? I'm guessing it was below freezing? Also, your icon next to your name is the green G. Are you also located in wi or just a fan? I'm actually in the greater GB area. Sent from my Pixel 4 XL using Tapatalk

This is the first time I've heard of it happening without using the block heater. Keep us updated if it continues. Sent from my Pixel 4 XL using Tapatalk

So this is my experience over the last few days. Unfortunately/fortunately we are through the sub-zero temps here for a while in Wisconsin. Attached is a spreadsheet of my data collection. My dealer called on Monday asking me what I had experienced, so I sent them this file without the last few days of information. I have yet to hear back from them. Truck Troubleshooting Data.xlsx

I agree, I hope this is all that is needed until they can fix the remote start part. I hope to hear your experiences if you give the block heater a shot!

Not sure I follow this. If you unplug the heater and then start the vehicle, the element should still be heated, thus I wouldn't expect it to be that big of difference. I'm not familiar with how hot the element gets, but the engine is never at 160 when I start it after using the block heater, so I have this hunch that it doesn't get crazy hot in the first place...? Maybe? But, I'm pretty sure that it's not getting above the boiling point of the coolant, which is then when I would expect the "water on a light bulb" scenario to happen. Idk, I'm just speculating and thinking aloud. Again, thank you for your input!

I appreciate your input. So you are experiencing what the dealer is, that if it's not being remote started, you have no issues. To clarify, do you plug it in above 0 degrees F?

Do you have a reason behind this? Or is it just so you don't drive away with it plugged in?

Dealer called again. They want me to take the truck back over the weekend and do more testing as the temps are going to be cold enough to test again (though only Sunday when the dealer is closed, and Monday morning). I was told to use the block heater, but only start it with the push button, not remote start. GM thinks there is a programming issue if the remote start is causing the issue. I'll report back as I test throughout the weekend. I'd love to hear what other people experience as well.

Dealer just called, they needed verification of info to give to GM. They asked if 1) was the vehicle remote started or push button started: remote started and 2) was it still plugged in when started: yes This morning they tested (at the dealer) at above 0F temps. They tested by leaving the vehicle plugged in, but used the push button start and did not have the fan issue. Maybe this is a workaround? Anyone else willing to try this on their vehicle? (Above 0F, powered block heater, push button start).

Doing some digging with my weather station data (smarthome), I found the following: From my smart plug that triggered the block heater, I "plugged it in" at 8:33AM Real weather data pulled from weather station sensor on my roof at 8:30am says +2.0 degrees F, while my smart mirror (openweathermap data) said -5.28 at 8:24AM (so I fed them wrong information here). Again, my weather station said that at 9:30AM, the temp outside was +2.4 degrees F, but openweathermap says -1.86 at 9:34 (again I told them it was negative temps when I started it because I was looking at openweathermap data, not the sensor outside my window, but in reality it was above 0F). I looked back at the video I took at 9:32AM of me starting the truck to confirm the actual start time today. I called the dealer back and notified of the actual temperatures, not the openweathermap temps as this is vital to the troubleshooting process I'm sure.

Dealer called, they are in contact with GM. They asked if 1) it was parked outside last night: yes, 2) temperature when it was started: -4F. They stated the the issue is not that it was plugged in above zero, but that it was unplugged above zero. To which I asked, if I had it plugged in overnight, unplugged it at -1F, and started it 20 minutes later when the outside temp is say 0F or 1F, assuming the engine coolant temperature were still warm, would it still cause the issue? Regardless, my service rep is doing a great job, but he is going to contact GM again with my answers as well as see if there is some workaround. The fact he did not explicitly say there is a fix and we are going to try that is not the most promising though. The truck starts slow enough at 0 degrees F, and I would sure like to be able to reduce wear and tear on my engine by being able to plug it in at any temps below freezing honestly. It's ridiculous this is even a thing. There are things that technology is useful for, and this is not one.

Yeah, the thing is, thats not a GM Technical Service Bulletin, and, well, my service tech said there wasn't a TSB for the issue. That is just an article that explains our problems I guess. I'm sure it's still helpful though.

No change this morning, the fans still running when using the block heater. Brought it to the dealer with the fans running this time and they are going to have another look at it. They initially wanted to blame it on the recent coolant exchange, but I disagreed. They are going to look more into it and research any software updates. Again, I'll keep this updated as I get notified.

Received the truck with a new water pump installed. I'll test out the cold start with block heater in the morning. Keep you updated as well.

Yup... you're gonna wanna sit down for this. "The coolant was low. That's why the fans were running." They found a coolant leak on the water pump. They will be replacing it tomorrow. I'm not an expert, but I'm pretty good with vehicles. It's been cold and snowy etc, maybe I wouldn't have noticed a puddle forming under my truck, but one would think that if the cooling fans were running hard (like we've experienced) due to low coolant levels, then there should be a CEL or some driver information center warning that the coolant is low. I don't believe this is the cause, but hey if they found a leaky water pump and are going to replace it under warranty, be my guest. But when I get it home, I will be plugging in the block heater and testing it out. I'll keep this thread updated with my findings. Sorry it's going to have to wait a few more days.

Dropped it off at the dealership this evening. They said there was no service bulletin for this issue and they were not aware of it. I printed off this article and left it with them since it explains it better than I can. I will have more information tomorrow. I am not aware when my truck was manufactured, but it is a 2020 model.

So it has finally gotten cold enough here in WI to test this out. This weekend I plugged in the block heater and started the vehicle when it was below 0F, but the fans still kicked on. The ambient air temp of the truck claimed it was 10F, but that was obviously wrong. It's possible that is why the fans kicked on. Regardless, I am going to call the dealership today to find out the status of an update. Hard to believe that there wouldn't be a fix for this when there are articles online dating back to 2019... I'll post back with an update later today.

I also have the torque app but I do not see a DPF percent option, I only see DPF differential pressure. Can you help me in finding this information in the app? Thank you much!