2011 Tahoe/New introduction and help wanted post.

[Savageshooter]

Hello everyone who might still be around. I did happen to replace the negative ground cable. Which btw is a huge pain in the tail! I had to remove half the bumper to get to the front wire. Man what were they thinking. Anyways, still having issues. I assume there would be other grounds? Anybody know where the others are located? Also, I have a picture of what the vehicle does. Just sitting at idle in a drive through line, rpms start acting weird, vehicle nearly stalls unless you give her a little gas along with the brake. Then we get what's in the picture. Not sure what's causing it to snap and throw this code or put it in this mode. Any thoughts would be appreciated.

 

[bobby2175]

So, I lived this nightmare on electrical - almost got rid of the truck because of all the money I spent with dealers with minimal success (think $4,000 replacing expensive parts of the electrical system) - until I found this site and a few other videos. What I found is that the dealer was just following DTCs and then replacing parts - that doesn't work here. I could have solved all of this for around $100 and very little of my time!

Your issues are manifesting similar to mine, but not exactly the same. The service stabilitrak and almost stalling are common threads and makes me think you need to go deeper into electrical like others have said.

1. Start here and don't skip this step. Make sure your battery is in good shape - have it tested
2. Clean up the terminal contact points, cable contacts at the battery including the 175 mega fuse.
3. You've already replaced the negative cable (which solved my problem)! Make sure you not only reattached that hard to reach ground behind the bumper, but that you clean up the contact points. I peeled back the wheel shroud and reached through to get to that ground. You can't actually see it - you have to do it blind and then confirm with your phone camera. It's ideal for someone like you that knows how to remove the bumper as you will then have great access and can do a thorough clean job at that point.
4. There are two grounds on the frame below the driver's seat - very easy to access - you hardly have to get under the vehicle.
5. There is a ground strap that goes from the firewall to behind the engine. Inspect that strap. You cannot really access the point behind the engine. If that strap looks to be in bad shape, you will need to create a new ground for it. I haven't gotten here yet, but will when I do big 3/4.
6. There is also the positive battery cable that goes from the battery to the under hood fuse block on the driver's side. I've heard of people having issues with this cable although my issues don't seem to be from here. It's an easy cable to access. I'd pull that cable, check the contact points at the fuse block (also easy to remove, clean and reseat). I have not yet replaced the cable, but if I was still having issues after everything else, I'd go there. I had already purchased the new cable and a new fuse block out of frustration on these issues and was going to do a full swap of everything until that negative cable solved my issues
7. I've been applying a thin layer of dielectric grease at each location I've been cleaning up
8. There are some additional grounds up front in and around the dash/pillars, but I have not gotten here yet.
9. I've learned that part of routine vehicle maintenance for this truck is making sure the grounds are in good shape.

Let me know if you need any pics or videos. I did a lot of research along the way, but it seems like you know a lot more about cars than I do!

Don't give up on this like I almost did. I love my truck again after getting help from everyone here, having now driven about 2,000 miles with no issues, and now having enough confidence to take the truck down to Florida from Michigan next month with the family - that's saying a lot after almost 5 years of electrical issues that made the truck not driveable and it spent a lot of time in the garage.

 

[alpha_omega]

I’d say that @bobby2175 (hopefully) hit the nail on the head for your issue.

If you look up “Big 3 Battery Cables” you should find plenty of threads pertaining to this fix - what size and style of wires to use, which wires need replaced, which wires go where, what can be reused, where new ones need to be added.

If you have already properly cleaned the throttle body and MAF sensor, and checked all of your plugs and plug wires, then your next step would be an overhaul on the battery cables. Let us know your results once you get those cables (and possibly a fresh battery if needed) swapped out. By chance if cleaning the throttle body and installing new wires doesn't fix your problem, then there are a couple other things that could be the issue. However, chances are it’s the weak power and ground wiring these vehicles have. Best of luck, let us know if you have any issues /questions and keep us posted of your results.

 

[Doubeleive]

I will just say that at 185k you should expect to experience some failures, the dreaded 160k+ mile mark is when things will need to be addressed if they haven't already left the party
things like
heater hose T's & heater hoses
water pump
radiator
alternator
maf
throttle body
transmission
front differential
front wheel hubs
control arms
ball joints
bushings
tie rods
if there is rust
then add brake lines and any modules attached under the vehicle and any exposed wires

these are just typical things due to the mileage, they may happen one at a time or all at once, this is often why people decide to sell them at this mileage rather than invest money into fixing it.

this is just the way it is.... so don't get discourged once you have a good baseline of what has been addressed you will be good for a long time.

 

[bobby2175]

For reference, here are all of the codes my truck was throwing on 1 day (3/21/22) when I had the electrical gremlins and had the truck in the dealer - C0242, C0561, C0590, C0615, C0895, P069E, P0700, U0073, U0100, U0100, U0101, U0121, U0140, U0170, U2100 - only 3 were history.

 

[Doubeleive]

For reference, here are all of the codes my truck was throwing on 1 day (3/21/22) when I had the electrical gremlins and had the truck in the dealer - C0242, C0561, C0590, C0615, C0895, P069E, P0700, U0073, U0100, U0100, U0101, U0121, U0140, U0170, U2100 - only 3 were history.

when you get a bunch of random codes that is a clear indication that there is a bad ground or an interuption in the lan bus, like a shorted wire or broken wire or wire touching another wire
you can try and find it by feeling all the wires, lift them up and run your fingers over them and feel for any cracks, pinched harness, rubbed spot, use a flashlight look everything over, typically when the wires are resting on something that is where they will rub thru or break

 

[Savageshooter]

So, I lived this nightmare on electrical - almost got rid of the truck because of all the money I spent with dealers with minimal success (think $4,000 replacing expensive parts of the electrical system) - until I found this site and a few other videos. What I found is that the dealer was just following DTCs and then replacing parts - that doesn't work here. I could have solved all of this for around $100 and very little of my time!

Your issues are manifesting similar to mine, but not exactly the same. The service stabilitrak and almost stalling are common threads and makes me think you need to go deeper into electrical like others have said.

1. Start here and don't skip this step. Make sure your battery is in good shape - have it tested
2. Clean up the terminal contact points, cable contacts at the battery including the 175 mega fuse.
3. You've already replaced the negative cable (which solved my problem)! Make sure you not only reattached that hard to reach ground behind the bumper, but that you clean up the contact points. I peeled back the wheel shroud and reached through to get to that ground. You can't actually see it - you have to do it blind and then confirm with your phone camera. It's ideal for someone like you that knows how to remove the bumper as you will then have great access and can do a thorough clean job at that point.
4. There are two grounds on the frame below the driver's seat - very easy to access - you hardly have to get under the vehicle.
5. There is a ground strap that goes from the firewall to behind the engine. Inspect that strap. You cannot really access the point behind the engine. If that strap looks to be in bad shape, you will need to create a new ground for it. I haven't gotten here yet, but will when I do big 3/4.
6. There is also the positive battery cable that goes from the battery to the under hood fuse block on the driver's side. I've heard of people having issues with this cable although my issues don't seem to be from here. It's an easy cable to access. I'd pull that cable, check the contact points at the fuse block (also easy to remove, clean and reseat). I have not yet replaced the cable, but if I was still having issues after everything else, I'd go there. I had already purchased the new cable and a new fuse block out of frustration on these issues and was going to do a full swap of everything until that negative cable solved my issues
7. I've been applying a thin layer of dielectric grease at each location I've been cleaning up
8. There are some additional grounds up front in and around the dash/pillars, but I have not gotten here yet.
9. I've learned that part of routine vehicle maintenance for this truck is making sure the grounds are in good shape.

Let me know if you need any pics or videos. I did a lot of research along the way, but it seems like you know a lot more about cars than I do!

Don't give up on this like I almost did. I love my truck again after getting help from everyone here, having now driven about 2,000 miles with no issues, and now having enough confidence to take the truck down to Florida from Michigan next month with the family - that's saying a lot after almost 5 years of electrical issues that made the truck not driveable and it spent a lot of time in the garage.

Hi Bobby and thanks for the details and information. I'll be certain to check these grounds and the other positive cable. I replaced the cable that is the main battery + clamp that has the alternator cable and the other cable you mentioned bolted to it. This cable just ran to the starter so I will be sure to check those other cables. The one going to the alternator looked fine and is the easiest. The grounds I will go over those very carefully. I suspect there is something with this as well. I cleared all my codes yesterday and drove the vehicle with the traction control and stabilitrak turned off on my way to work. I drive about 20 ish miles one way. I checked for my abs correlation code and it hasn't shown back up yet. My plan is to drive the vehicle and get as many miles on it until it starts to show up again. It has typically been many miles before it shows up. Say maybe 200 miles since codes being cleared before it shows any issues. Again, I will go through all these cables and begin the process of checking and verifying.

Thank you for the help.

 

[bobby2175]

This sounds so much like what I went through. I'd go 100s of miles and then it would show up. I turned traction control off in hopes that would do it - it all failed. Spend the time on the cables and I'm hoping it takes care of it!