Jsdirt

Anything built before 1996 can sit for months, and still fire up without issue. I just had to move a '94 Ram in my yard - I haven't started it in over 6 months. Didn't even need a jump pack, lol. On the other side of that is my '07 Silverado 1500, with the myriad of computers, & wiring. Since I've taken it off the road, I have to throw the charger on it at LEAST every 2 weeks. Those damned magic boxes just constantly draw. Even the EVAP system does a seal check when parked with the right fuel level. I get a minimum of 9 years out of batteries in all my 30 year old or older vehicles. Usually 10 or more. Can't get more than 6 out of a 21st century model.

Sounds like a low voltage or bad ground issue. Connect a set of jumper cables to just the ground on the battery, connect a length of wire to whichever side is grounded, then stick a pin into the ground terminal of any of the non-operative lights & connect the wire to that. If everything suddenly works, you've got a bad ground. Make sure the pin is making contact - sometimes they won't when you think they are, and that'll skew your test. You'll need a meter to see if you're getting battery voltage, or close to it, to the lights as well if the ground circuit checks out.

Sorry to hear that. What a PITA! Been there a hundred times over the years with my own modern junk, and customer's. Reason #1 why I've always hated electronics in motor vehicles. It's great when it all works ... but when it doesn't, it SUCKS! The wiring on these leaves a lot to be desired, so that's a distinct possibility that there's a wiring issue. The later models are even WORSE, so be glad you have an '06. Every generation they find a lower bid on parts. It's awful. I took my '07 Silverado off the road and bought a '93 W250 with a Cummins 12v & 5-speed. At least I can fix this one without tearing every last hair out of my head!

Yes, the TCM is internal to the PCM. Was the torque converter replaced (I hope)? This vid might help with troubleshooting.

There's got to be a way to tune this out. If not, maybe a year down the road there will be.

Makes me glad I took my '07 off the road and went to a 1993 diesel. The hell with that crap! My '07 does that a little bit, too - usually when you need the punch the most! NO vehicle should jeopardize your safety because a manufacturer is too cheap to built parts that can handle the engine THEY designed! Especially when you're paying $100-LARGE PLUS for a friggin truck!

2024 ... yikes. Good luck with that! Too many electronics, too much emission crap. Could literally be any one of 10,000 individual things, or systems, or modules on that thing. That's the dealer's problem. If they can't fix it, make them get you another one. And if they ALL do this, then get out from under it, flip GM the bird, and buy something else from another brand. On a 6-figure $$$ truck, that problem is UNACCEPTABLE. Full stop!

Yep, another common failure point. So many it's hard to keep track these days!

A '16 engine in a '08? I'd steer clear of that one. If you're determined to make it work, expect HOURS of research and frustration. You'd be MUCH better off going backwards, putting an older engine in the '08. They're tried and true and reliable for the most part. That said, keep in mind, going pre-2007 GMT-900 series, or 2007 classic (GMT-800) will require a crank reluctor change from 24x to 58x. Not an easy task. If you want an "easy" swap, stick with 2007-2011. Preferably 2007, so you don't get VVT - one more thing to fail, and cause wiring nightmares trying to make it work if your truck didn't come with it. I say "easy" because NOTHING is easy on these trucks. Hopefully you at least got a rust free one, otherwise get ready to do battle! BEEN THERE, and quit auto repair not long afterward!

You've clearly got an electrical issue. You need to find another shop that's well versed in electrical troubleshooting. These days that is a MUST. Not everyone has the skills (Or the patience / motivation) necessary to find electrical gremlins in modern vehicles. The newer the vehicle, the more difficult troubleshooting becomes. That said, STAY AWAY from ANY dealer. Find a local, non-dealer shop that has good reviews online, and that the locals speak highly of with electrical issues. This one seems to be intermittent, and is going to take some skill to nail down.

It used to be a simple cable connected to the shift lever that yanked on a flag (God I miss those days!!!). In this era, the signal is sent by that black box hanging off the side of your transmission with the shifter "crank" connected to it. That's the neutral safety switch / range sensor. You could try spraying that plastic piece that turns with the shift shaft, with silicone spray lube & see if that helps. It's cheap and you've got nothing to lose at this point. If it doesn't work, replace the range sensor. https://www.rockauto.com/en/catalog/chevrolet,2002,silverado+1500,4.8l+v8,1380158,electrical-switch+&+relay,neutral+safety+switch+/+range+sensor,4584

You would need to know the amp draw of a few good fans, and compare that to what yours are drawing. I suspect the fans are dying, and requiring more amps to move than they should.

Good deal. Would be nice if GM could make a friggin pump that lasts. They used metal, it rusted. They use plastic, it cracks! You can't win today. Meanwhile, my '86 Grand Marquis just turned over 300,000 miles on Wednesday morning, on the ORIGINAL in-tank electric fuel pump (and the ENTIRE driveline, minus the u-joints)! Was the 1st year of multiport injection. 37 years, 300k, ZERO LEAKS!!! Proof that it can be done. Automakers just refuse to. Lately GM can't even get their 6.2 to make it to the first oil change without spitting rods out the oil pan!!

Should still be under warranty if you're under 36k miles. Let GM fix their crap engineering.

Any codes? If your smelling fuel, there should be an EVAP code either pending, current, or history in the PCM.

The problem with this generation truck is, there's a computer in the mix. Nothing simple like the earlier days of just power, ground, a relay, and the control side of said relay. That was too simple for automakers. They wanted to save a buck on fuel filters and return lines. Now you've got a FSCM - fuel system control module which varies output based on demand, which eliminates the return side of things. Same things still apply to the pump - still needs good power, ground, and functioning check valves in the pump itself, but the computer throws a whole other world of possible failure modes. If the FSCM fails, you can't just replace it - it has to be programmed to the vehicle with a J-box and subscription (More $$$ to GM). All that said, a long crank / slow-to-fire symptom is usually a check valve in the pump that can't hold fuel pressure when the vehicle is off. So, every time you turn the key to start, the pump has to refill that whole line again - that's why the long crank time. Air and spark have nothing to do with that issue. On the point of what mileage things fail at, today, it's a complete crapshoot. Some don't even make it off the lot, while others go longer than the engine or transmission does. Nobody knows. It's the luck of the draw as to what you'll get. On my '07, that was one of the few things on that truck that lasted. Everything else failed during warranty, or before 100k. Get a pressure gauge on there somehow and see if pressure is bleeding off whenever you kill the engine. If it is, you've found your problem, and the only fix is a new pump assembly. EDIT: Just remembered on this one you can use the scan tool for fuel pressure, so long as the sensor is reading correctly.

I would focus your attention around the throttle body, and especially the wiring to the actuator. Those have been problem areas on past GM trucks. Can't recall for certain, but I believe there was a TSB out on that particular issue - any time the throttle body was replaced it was required to replace the pigtail as well.

There is ZERO reason to take a ten year old vehicle to a dealership, unless you enjoy a 300% markup on a repair any competent private garage can do. They don't call 'em "stealerships" for nothing! Now I have to say this before someone gets their feathers ruffled, even though I feel like a broken record ... THIS IS NOT BECAUSE OF THE TECHS WORKING THERE. It's because of GM corporate! They screw the techs as badly as their customers. If I never give another PENNY to GM again in my life, it'll be too much money! OK ...this screams of a bad connection somewhere. Since your an HVAC tech, troubleshooting isn't a foreign concept to you, and you'll be able to track this down with a wiring diagram. The shitty part about this is you have to pay for service info. That's the world automakers have created today. They've built vehicles so complicated that working without one has become just about impossible, unless you have endless hours to spend under a hood ... which owning your own business tells me, no F'in way is that true! If you want to fix this, and any other issues down the road, you'll need at a minimum a good scanner. The basic ones will only read codes only in the PCM, but if you spend more money you'll get bi-directional control (Makes troubleshooting by yourself 1,000% easier), multiple module code-clearing capability, and good live data. Would be good to be watching live data when the problem happens. If you suddenly lose communication with the PCM from the scan tool when the issue happens, then you can focus on checking powers and grounds to the PCM. Best thing you can do right off the bat, just to rule out any issues is do a THOROUGH visual inspection of ALL wiring. Focus on areas of heat and vibration. ANY areas where the harness contacts metal, no matter how protected they look, are suspect. Wiring today is made by the lowest bidder. You've got over 1,000 miles of it in that truck, and just ONE wire can cause this. Sometimes just a good visual will reveal an issue. Takes LOTS of patience, however. Next course of action if a visual turns up nothing, is to remove ANY ground you see - including the battery ground (And positive just to be sure) - sand / wire wheel / brush where it contacts & the bolt, and reinstall. I mean ANY ground wire you see - behind the engine, driver's side of engine by P/S pump, under the truck - do 'em all. Give them a tug and make sure they're intact. Check the fuse box under the hood. If you see anything green, that's bad. That's corrosion of copper. Green in any connectors or wiring is bad as well. We see it a lot up here in the salt belt of MA. Something you'll probably never see as an HVAC tech is wiring so shitty that it can and will break INSIDE INTACT JACKETING! I've seen it 100 times! If a wiggle test reveals a problem area, tugging on that wire with a hand on each side of the suspected issue (Like you're trying to pull it apart) can sometimes stretch the jacketing - a dead ringer for broken copper strands inside. I wouldn't have believed it if I hadn't seen it for the first time over 7 years ago on something much older than yours. If all that fails, go to https://www.alldata.com/diy-us/en/diy-repair-information and grab a diagram. Will be the best money you ever spend. Keeping your symptoms in mind & focusing on those systems that could cause this particular issue should get you zoned into the right wiring. The last option is if you don't want to be bothered with any of this, just research local NON DEALER shops in your area with good reviews. Check all the different places for reviews - Google Maps, Yellow Pages, etc.. Go with the best one - particularly a shop that does a lot of electrical & driveability troubleshooting, and just wash your hands of it all.

Would be super helpful if you could post the code meanings. We don't know what they mean. We're all not walking encyclopedias of auto repair. There's just TOO MUCH to memorize these days. Most things have to be looked up. So codes coming and going indicate an intermittent. Those are lots of fun to diagnose. Just ask any tech. You'll have to get a good scan tool on there and do a wiggle test of the harness & connectors, while watching for a drop out or glitch in live data. Even better, watching a scope for the drop out to try and pinpoint which wire, or pin in a connector, is frigged up.

Sounds like it was a bad connection. Any time power is interrupted to the vehicle by disconnecting the battery, everything will be cleared - codes, drive cycle monitors, radio presets, etc.. There's nothing to "reset".

Google must've been monitoring my post - just got an email with a link to the exact thread I was talking about: https://www.performancetrucks.net/forums/member-made-tools-parts-classifieds-197/tru-cool-max-trans-cooler-4739-47391-install-kit-brackets-fittings-hardware-508374/page69/ Sorry for the poor wording - I didn't mean THIS forum, but I see how it came across that way. My bad. EDIT: I see you already ordered one! Saw your post there. Said "yesterday", so I was confused ... but it's 1am, so that explains it.

I highly recommend a Tru-Cool unit. About the biggest cooler you'll find for a pickup truck. I've been using one in my Silverado since 2020 with excellent results. If the trans gets hot in traffic, or on a long hill, as soon as the converter locks at speed, that temp plummets before your eyes. I've watched it drop 30° in minutes. I live in MA, but the high summer humidity makes cooling that much more difficult. Out there in the dry heat, it'll work just as good, if not better I'd wager. You can shop around for price - this is just the first place that popped up: https://www.oregonperformancetransmission.com/product/LNG-47391.html I got mine here: https://www.dieselsite.com/ You'll have to get adaptors for the cooler lines. Bypass the radiator cooler completely. Makes a BIG difference in a GOOD way in cooling, contrary to popular belief. That's how mine's been hooked up for the past 31k miles of hard towing in hilly New England, with a few trips down South in the heat. An installation kit helps as well. There's a guy on this forum here that's been building & selling them forever. I bought mine here. 1st one I ordered got lost, then when it arrived, the adaptors wouldn't thread into place. I think he sent adaptors for a GMT-800 series truck instead of the 900 series I have. The installation kit worked beautifully, though. I can't remember the name of the forum - you'll have to check out the vid below. I also got trans lines from this place. You probably won't need to do this living in AZ, since metal lasts an eternity there. For anyone else reading that lives where metal disintegrates thanks to winter road salt, I bought my lines here: https://www.linestogo.com/ I've got a YouTube vid of the install. My attitude SUCKED in the video, since I was pretty pissed off my 103k mile 4L60E decided to take a steaming dump on my finances. Plus, it was election time ... and we all know how that turned out ... This is Part III of the install, and shows the Tru-Cool install. Mine's an '07 don't forget, but the install should be similar in many ways. You can run metal all the way to the cooler, or, you can run rubber like I did - just have to use GOOD hose, GOOD clamps, and BARBED fittings so they never come off.

I'd take a look inside the MAF plug and make sure you didn't bend any pins over when plugging it back in, and/or pinched a wire or 2 in something. Also, if you installed a K&N air filter, or any filter that requires oil to trap dirt, over-oiling can cause all kinds of problems. I'm not too familiar with these newer ones, but that doesn't seem related to over-oiling - seems like some kind of connection or wiring issue.

14 years in auto repair and I've never heard of that parameter. I wouldn't put much stock in what that's telling you. As far as making power, even modern engines are the same as the old days. Gotta make 'em breathe. Free'er flowing exhaust, uncorked intake (Cold Air Intake, bigger / free'er flowing air filter), and more fuel all add power. The 8.1 should have a completely different power delivery than the gutless-off-the-line 5.3. Should have the opposite power, actually - all right there the moment you hit the pedal, then signing off much earlier than the 5.3 in terms of revs. The 5.3 doesn't even start making decent power until 3k RPM - kind of the opposite you want for towing. That 8.1 should have a good chunk right from the bottom, and pull nice all through the midrange. A clogged catalytic converter would REALLY choke up that engine. Kills both power and fuel mileage. If it were mine, I'd look into a cold-air intake, free'er flowing cats (if required in your state), long tube headers, & a complete system from the headers back. Will cost a bit of cash and be a bit of work, but the payoff will be well worth it. More power with not much change in fuel mileage -if anything, mileage will be better. A win-win.

Indeed - make GM fix their f'up! Once it's out of warranty, bring it ANYWHERE but. I usually say that right out of the gate, but I must've read fast and glossed over the fact that this is a '23 model. Hopefully you get a tech that hasn't been screwed all week by corporate, and puts some troubleshooting time into this one. Fingers crossed.