Shawn T

We recently went on a camping trip and I noticed that the climate control was acting finicky. It was 80 degrees F when I got to start my truck to take a drive. The auto-cooled seats did not come on nor did the climate control act like it wanted to cool the cabin down very rapidly. I looked at the ambient outside temperature on the dash and it was 53 degrees F. I drove the truck for several minutes and the temperature did not recalibrate, it stayed at 53 for the remainder of the day. That afternoon, I decided to disconnect the batteries for about 10 minutes and do a hard "reboot". I started the truck back up and the temperature read 91 degrees F, almost a 40-degree delta. Well, I just figured it was a lot closer to the actual ambient of 80 degrees and turned the truck off for the day. The next morning I checked the ambient temperature (thermometer and phone app) and it was 64 degrees F. When I started the truck up, the temperature was at 91 degrees again. We hooked up the 5th wheel and traveled home, going over passes and on the I-25 corridor when morning temperatures were constantly in flux, and the truck thermometer dropped to 86 degrees F at one point when the actual ambient was just above 70 degrees. When we got home it had climbed back to 91 degrees again and stayed, only about 5 degrees high for the ambient at midday. I see a few posts on this topic in the forum where the truck is taken into the dealership and they throw parts at it, mainly the outside temperature sensor. I have owned dozens of GM vehicles with ambient temperature sensors since the late 90s and never experienced a bad one, although they may be a little inaccurate, nothing like this. Are there any other issues that could be causing this before I take it in?

I gotcha, and you are correct you don't have to set up the camera to get the preview. I have plugged it in several times and it is black. I plugged it into my buddy's 2021 and it displays an image on the preview. I guess, I'll be purchasing a new camera and trying to offload this one. If you do find the part number, it would be highly appreciated. I'm not going to buy it this season, I have the camera and display that came with the camper to get me by.

Thanks man, I'm thinking you're right because when I opened up the camera when I had my '20 I plugged it in and hit preview on the app. I would almost swear an image popped up before I ever mounted it, or programmed all of the dimensions in. The dimensions were just for the "invisible" mode to look halfway real. You said you were able to purchase the camera alone, separate from the cable and the housing?

You know what I just plugged it in, I thought I could get a preview that way. I'll have to go through and program the trailer into the app and check it out. Man, I feel stupid now, it's been 5 years since I did it last.

I just recently towed my 5th wheel with my '24 GMC Denali. I had an identical truck, a '20 model when I purchased the camera. Is there different firmware for the '24, do I need to get another camera? When I hit the preview, all I see is black. It recognizes it.

The measurement for the camera is taken from the bumper of the truck to the rear wall (mounting position) of the trailer. My 33-1/2 foot 5th wheel is ~30' from the truck bumper to the back. You need the 50' of cable though, because it needs to go from the center of the rear wall, under the trailer body, and out of your pin box, with enough slack to plug into the bumper harness. The invisible trailer function is almost pointless, it cannot figure out why the camera on the cab is so close to the trailer body. It looks funky but the truck camera mirrors jive with the rear trailer camera and give you a decent field of view behind the trailer and to the sides. GM dropped the ball big time, 5th wheels should have been the main priority on the invisible trailer function IMHO. Also, having to mount the trailer camera tailgate high is a nuisance too. They should have come up with a technology to adjust the elevation and allow the camera to be mounted on the top edge of the back wall.

No there is not horizontal calibration, you will have a lopsided view. I guess you can always mount it tailgate high, in the center of the door and fabricate a make-shift, removable bracket so you can remove the camera and hang it off to the side while unloading? I don't know, I was really unimpressed with the actual functionality compared to watching the commercial on TV. A remote system with very small camera would be ideal. My 5th wheel has a large storage compartment under the rear bunk that has a large on hatch on the rear (almost like a toy hauler). I had to run the cable around the opening and down the door from above it's center. It looks very gawdy with the black cable against the white exterior. And no, it does not clearly state that the cameras do not function with the "invisible" trailer when you have a 5th wheel, I just learned the hard way after the purchase.

"Invisible" trailer is not available on 5th wheel or gooseneck profile because the cab camera is too close, and not correctly relative to the tailgate camera. I have created a bumper pull profile for my 5th wheel and you get a real funky fish eye version of invisible trailer. The tailgate camera and cab camera cannot sync but it serves the purpose of seeing behind the trailer and down the sides using the mirror cams. My 5th wheel is 33-1/2" feet, just under the maximum allowable profile length. I had just enough cable to mount the camera, tailgate high, on the rear of the trailer. I routed the cable from the camera over to the side and down underneath. I ran it under the winter skirting and popped it out the hole where the opening for the pin box is (this is very important, you do not want to pop it out beneath the front of the trailer and plug it in, you will not have enough slack to make turns). I have just enough slack to plug it into the bumper plug and be able to back it up making 90+ degree turns.

I agree, the bolster is too short. With that said, I have been on 6-8 hour trips with no fatigue. I find this kind of funny though, I ordered and received my '15 in summer of '14 and my only complaint was the tilt/telescoping column eliminated the true "tilt" of the wheel and I took some heat over it. Folks are still complaining about it 6 years later and praising the last generation, when the concept was identical. The tilt radius has been increased so much by moving the tilt joint closer to the firewall, that it's essentially an up-and-down adjustment. It was a problem seeing the instrument cluster in the last generation, as well, when the seat and wheel was in the most ergonomic position for me. Now a tilt/telescoping wheel and seat design from a 75 El Dorado would be an improvement on these trucks. ?

Beautiful truck! BTW factory LEDs are marginal at best. Maybe it's may eyes but my '06 with reflector beams was like a beacon compared to my '15 with projectors. The projectors on my '15 seem to have been better on high beam than the LEDs on my '20. Maybe I'm just getting old!

I fear all of these discussions will be moot points within the next decade. GM's mandate to be 100% EV in all cars, and light duty trucks by 2035 will probably create a lame duck 4-5 year period for gas and diesel while they develop electric motors for the HDs. With the torque curve of EVs, they will probably be going to CVTs, who knows. I love my Duramax trucks, and have for 18 years. Going to hate to see them killed off.

It seems like every time the big 3 redesign their HD pickups they up the payload and tow rating and the ride really suffers big time! My last decent riding HD was my 06 Duramax. I ordered my '15 with 20" wheels and I can tell you the ride from my 06' was significantly rougher! I ended up mounting some Cooper tires, 2 sizes up and running as low air pressure as the idiot light would allow and it helped a little. My '20 has the same size tires as the Coopers on my '15 from the factory with 20" wheels, and it rides about the same. Pretty teeth rattling, everything stock. In the old days, lifting a truck meant sacrificing ride quality. Now it means greatly improving it, I agree with gSwift, Fox shocks with external, adjustable reservoirs are the way to go. I have also avoided the off road package since GM went away from Bilsteins for good reason, Ranchos suck. I guess I didn't learn my lesson because this truck has the off road package and it came with Ranchos. I only have 15k miles on the truck and both rear shocks have ruptured (replaced under warranty). My dilemma is wait the warranty period out or just replace them with Fox' and have the product warranty. Another thing I noticed is that Goodyear tires seem to ride a little stiff with comparable air pressure. Maybe that's just me though, I like a good Cooper or BFG myself.

I have always owned Duramaxes (LB7, LBZ, LML, L5P) and they have been bullet proof, grant it they have been personal, not fleet trucks. The big thing for me is that GM perfected a diesel motor in 2001 and has stuck with it. The '21 marks the 21st model year and they are on the 6th revision of the 6.6L Duramax. The Allison transmission has evolved from a 5 speed, to a 6 speed, and now a 10 speed. Again, honing perfection. I have friends that are died in the wool Power Stroke and Cummins drivers and they both have the same gripe. When ford went away from the Navistar 7.3L the dependability and maintenance costs went through the roof. The RAM guys are the same, the 6.7L is nowhere near as dependable as the 5.9L. If something is dependable and long lasting why try to change that, just strive perfect it, as GM has? Look at the Chevy small block, it's living proof.

It sounds as though every dealer is "handling" this differently. Mine tried to say a TSB doesn't mean that it's covered, only that they are going to get bum-rushed with the issue. I called BS on that! The next excuse was the wear parts only carry a 12 month/12,000 mile warranty and if it's not a recall, the warranty language kicks in. I just decided to pull the "loyalty" card on them and mention the 3 GMC Sierras, and 2 Cadillacs that we have purchased there and that I will just take my business elsewhere from here on out. Long-story-short, the service manager "pulled some strings" with the factory and they covered it. I have new pads on all four corners, rotors where not glazed, and only time will tell.

They will start squeaking again, I did the same experiment with brake clean. They are considered wear parts and even with the TSB the dealer may try to get out of replacing them after 12k miles. They did with me any ways and I just pulled the "I'm not picking up my $80K pickup truck with crappy, noisy brakes on it, until something is done". Essentially I buy all of my vehicles from them and they felt compelled to talk with the factory and get it done. They put pads on all four corners. No squeak back yet. Mine got so bad that I avoided driving through busy parking lots because I would get looks from every pedestrian within 100 yards. Like what in the heck is wrong with that nice new truck?