redwngr

2020 has a much different accessory belt system than the previous generations.

Depends on what brand of fuel you purchase.

Throttle and brake pedals are at different levels to reduce the chance of operating the throttle when a big boot/shoe is only half on the brake. Adjustable pedals moved them closer/further from the seat together so the throttle/brake relationship remained the same.

My truck doesn't have it, be swmbo's gm ride does. When I drive her rig, I don't turn it off unless it annoys me. Between the times the day is too hot or too cold (out of temp range) or the HVAC hasn't got vehicle inside close enough to temp, or engine and trans temps aren't yet into range, or tow/haul is in play or it's a trip that has very few stops anyway I find that I often just let it ride. I've also learned to predict traffic movement an lift my foot off brake a little sooner so it will be started by the time I need the throttle. After it has activated, it can also be shut off by lifting foot off brake and then reapplying brake. It won't activate a second time during that stop. (I think that's because it requires a minimum speed be reached between auto stops) Anyway, I don't find it to be a big enough issue that I'd spend money to change it. ; I'm finding that the more often I drive it, the less often I shut it off. I can use one of the built-in override methods a lot of times for the cost of a plug in unit.

GM has release some info about trailering tech changes for 2021 HD and 1500. https://media.gmc.com/media/us/en/gmc/home.detail.html/content/Pages/news/us/en/2020/sep/0915-sierra.html 2021 GMC Sierra Offers More Innovative Trailering Tech as Americans Continue to Hit the Road for Outdoor Adventures Jack-Knife Alert, Trailer Length Indicator and enhanced Rear Trailer View join existing available camera technology on GMC Sierra 1500 and Sierra Heavy Duty to help drivers tow like a pro 2020-09-15 Print Email Add This DETROIT – At a time when towing is on the rise, the 2021 GMC Sierra 1500 and Sierra Heavy Duty will offer several new available features that build on the trucks’ strong suite of customer-focused trailering technologies. “Trailering is essential for pickup truck customers. More than half of our Sierra customers use their trucks to primarily tow equipment for outdoor adventures,” said GMC Marketing Director Rich Latek. “We continually listen to customer feedback, which tells us they want class-leading safety, technology and comfort to tow what they need, whether it’s a boat, an RV or a trailer hauling off-road toys.” These updates arrive as an ever-growing number of Americans are turning to outdoor activities that require a trailer. In a recent study, the RV Industry Association found that more than 46 million Americans are planning to take an RV trip in the next year. As a result, shipments of RVs have been increasing this summer and towable RVs make up about 90 percent of those sales.1 New or enhanced trailering tech available on both 2021 GMC Sierra light-duty and heavy-duty models includes: Trailer Length Indicator: New for 2021, when enabled and driving forward with the turn signal activated, the center console screen displays a red overlay twice the length of the compatible trailer and shows when other vehicles are present and may interfere with a lane-change maneuver. Jack-Knife Alert: New for 2021, Jack-Knife Alert tracks the position of the compatible trailer in relation to the vehicle. If the front of the trailer approaches the rear of the vehicle, an alert is displayed when there may be a potential jack-knife situation. Rear Trailer View now features guidelines and Trailer-Angle Indicator: Rear Trailer View has been enhanced to include guidelines that assist when backing a trailer into place and a Trailer-Angle Indicator to show the relationship between the truck and compatible trailer. Rear Trailer View requires the customer-installed available GM auxiliary accessory camera. Rear Side View enhancement: When driving forward on the 2020 GMC Sierra, Rear Side View provides a split view of the left and right sides of the truck and compatible trailer that is automatically biased based on the trailer’s angle. In the 2021 GMC Sierra, drivers will have access to this view while driving in reverse, making it easier to see surrounding vehicles and objects while positioning a trailer. Cargo Bed View enhancement: New Cargo Bed Zoom View and Bed Hitch Guidance are now available, which can be helpful for aligning and hooking up a gooseneck/fifth-wheel trailer. Select trailering features require a conventional-hitched box or camping trailer and additional setup may be required. Customers can see their dealers for full details. Additional updates for 2021 GMC Sierra 1500 Other additions to the 2021 GMC Sierra 1500 include increased availability of the MultiPro Tailgate on SLE and Elevation trims, as well as a new selection of colors. New available features on the GMC Sierra 1500 AT4 include 20-inch Goodyear Wrangler Territory tires and an off-road high-clearance step. The available 3.0L Duramax Turbo-Diesel, which provides an ideal balance of performance and efficiency with 460 lb-ft of torque and best-in-class horsepower while offering up to an EPA-estimated 30 mpg on the highway, is a popular choice for GMC Sierra customers. For 2021, the MSRP of the popular engine will be reduced by $1,500, placing it at $995 MSRP above the Sierra 1500’s 5.3L V-8 with Dynamic Fuel Management. Additional updates for 2021 GMC Sierra Heavy Duty New additions to the 2021 GMC Sierra Heavy Duty include enhancements to the trucks’ popular premium trims. HD Surround Vision and Bed View camera technology are now standard on Denali. The new Sierra HD Denali Black Diamond Edition will have several unique features, including exclusive 20-inch high-gloss black wheels and new power-retractable assist steps. Similar to the Sierra 1500, the Sierra Heavy Duty AT4 will now have available 18-inch Mud Terrain tires and an available off-road high clearance step accessory. Other additions to Sierra HD include the MultiPro Tailgate standard on SLE and three new colors.

If I'm reading this right... $218 vs $238 doesn't seem like a big deal. But the inspection for next renewal sounds like a pricey 'gotcha' thing. I'd plan on spending the $218 to convert at next renewal, instead of paying for an inspection to renew the D.

I'm surprised that the truck gets warm enough for auto stop/start to work during a 2 mile drive to work.

Instead of spending to add a cd to your truck, find (or purchase) a way to copy your cd music to a usb, You will be able to fit many many cd's on a single USB stick. Something like 10 music hours per GB if you use the mp3 format. (Of course if the collection is large enough you might use more than one) If your computer has a cd player and a usb port, you just need to decide which software to use. If your phone has enough storage you could use it to carry the music files. Online version of the Infotainment guide can be downloaded from GM here: https://my.gmc.com/content/dam/gmownercenter/gmna/dynamic/manuals/2020/gmc/multimodel/2020-gmc-infotainment-guide-3.0.pdf It has a bunch of information about operating the radio when playing from a usb, file types that it will play, usb formatting that is acceptable etc etc.

Are you running in 2wd?

Might start with the carwash and find out what they used. They may know what was used / why it happened and might even have a solution. I'm gonna guess your's isn't the only one.

Sounds like the techs are going to have to follow the other diagnostic procedures to determine cause of the abnormally standby draw.

Funny that supply and demand still works....

Sat with dealer today and got GM pricing on a 2021 1500. (and got all the summary print out pages) Didn't ask, but I'd expect they can also price the HD's. Other than from the dealer, I haven't seen anything published by GM that will even admit that any 2021 model pickups will exist -- unless you count the Canyon/Colorado, the mysterious Hummer, or the new SUV's. GM is holding back for a reason. Probably an interesting 'reveal' ahead. This is not the normal information flow for a new model year. ******, they've been providing pictures, videos and specs for the 2021 SUV's for since last winter, Normally the new pickups wold be showing up by now -- but so far, not a peep from GM. IF there are no changes to hide, there is even less reason to not provide pricing info.

This happen in cold weather? There is a tech article about parasitic battery draw in temps below 40F -- including diagnostic test to confirm if that was the source of the issue. Seems that some have an issue with one of the Seat Memory Control Modules (SMCM) waking up the low speed gm LAN Bus May or may not be related to the batteries needing replacement. Intermittent Parasitic Battery Draw Below 40° F/4° C June 16, 2020 Several intermittent conditions related to a low battery state of charge may be found on some 2018-2019 ATS, CTS, XTS, Corvette; 2018-2020 Envision, LaCrosse, CT6, Escalade, XT5, Equinox, Impala, Malibu, Camaro, Silverado, Suburban, Tahoe, Traverse, Acadia, Sierra, Terrain, Yukon; 2019-2020 XT4, Blazer; and 2020 XT6 models. The following low battery charge conditions may be present when the ambient air temperature is below 40° F/4° C for an extended period of time: Dead battery/required jump start Slow crank Battery low state of charge and, if equipped, Auto Stop/Start inoperative Instrument cluster backlighting turning on intermittently while the vehicle should be asleep Keyless or passive entry/start inoperative These conditions are not easily duplicated in the service bay or in temperatures above 40° F/4° C. These conditions may be due to a low battery state of charge that is being caused by one or more modules waking up the Low Speed GM LAN Bus. When the ambient air temperature is below 40° F/4° C, the Seat Memory Control Module (SMCM) could inadvertently wake up the Low Speed GM LAN Bus. All SMCM’s on a vehicle, including the Driver K40 (Fig. 9), Passenger K40P, Left Rear K40LR and/or Right Rear K40RR module, may apply. Fig. 9 Begin diagnosis by asking the customer or inspecting the vehicle for any aftermarket equipment. If no aftermarket equipment is installed, try to duplicate the conditions by leaving the vehicle outside overnight in temperatures below 40 F/4 C. Follow the Battery Electrical Drain/Parasitic Load Test procedure in the appropriate Service Information. If an excessive battery draw is duplicated, as part of the Circuit/System Testing procedure, remove the fuse(s) that powers the SMCM. The SMCM may be powered by more than one fuse. Wait several minutes to see if the vehicle will return to an acceptable battery draw level. If so, replace the appropriate SMCM. If the battery draw does not return to an acceptable level with the SMCM fuse(s) removed, then continue with the diagnostic procedures in the Service Information.

Interesting you just have hours. Pic at top of thread has all three. (total hours/idle hours/miles)

2019/2020 1500:, 2020 HD's AEF Window, power front, passenger express up/down Standard on SLE/AT4/Denali/ LTZ/HC Not available on other trims

Even after key / pushbutton is used after entering running vehicle?

Does it go away as soon as the truck goes to ACC or ON ? Does it do it if the remote start is used so truck is already running before door is opened? Lots of vehicles will display the odometer when the door is opened and ignition OFF. If it reverts to operator desired screen when electrical goes to ACC or ON, I guess I don't see the harm.

AFM vs DFM https://gm-techlink.com/?p=11880 Active Fuel Management/Dynamic Fuel Management on GM Models August 9, 2019 Active Fuel Management (AFM) or Dynamic Fuel Management (DFM) is available on a number of recent GM models to help improve fuel economy, including 2014-2019 Corvette, Silverado LD, Sierra Limited; 2015-2019 Escalade, Suburban, Tahoe, Yukon; 2016-2019 CTS-V, Camaro; 2019 Silverado 1500, Sierra 1500; 2020 Silverado 2500/3500 and Sierra 2500/3500 models. Active Fuel Management AFM was designed to provide maximum fuel economy under light load driving conditions by deactivating the lifters on specific cylinders. On V8 engines, half of the cylinders are deactivated and on V6 engines, two of the cylinders are deactivated. Under certain operating conditions, the Engine Control Module (ECM) commands the cylinder deactivation system to deactivate engine cylinders 1, 7, 6, and 4 on V8 engines or to deactivate engine cylinders 3 and 6 on a V6 engine. The engine will operate on all cylinders during engine starting, engine idling and medium-to-heavy throttle applications. The Lifter Oil Manifold Assembly (LOMA) is only used on AFM applications. Dynamic Fuel Management DFM is the next generation in cylinder deactivation systems. It features AFM technology with the additional ability to deactivate any combination of cylinder valves to optimize fuel consumption. The control of every cylinder event allows peak efficiency to be obtained throughout the range of engine operation. (Fig. 15) Fig. 15 By extending cylinder deactivation to all cylinders, DFM allows for a large variety of firing sequences. DFM can have rotating cylinder deactivation patterns, such as 1/5, 1/3, 2/5, or 2/3, as well as fixed patterns, such as 1/4, 1/2, or 3/4. For rotating patterns, which are only available on small block engine (L84,L87), the cylinders being deactivated can change with each subsequent engine cycle. Transitions between firing sequences is done in a continuous fashion, making the transitions seamless and transparent to the driver. Oil Control Valves (OCV), only used on small block engines, replace the LOMA. OCVs provide faster response times than the LOMA and are required for DFM. OCVs also are used on L82 engines with AFM. AFM/DFM Usage Model AFM VLOM 4 Cylinder Deactivation DFM OCV FDFM None Notes CTS-V 6.2L LT4 Yes Yes No No Always active Camaro 6.2L LT1 Yes Yes No No Automatic only. AFM not active with manual trans Camaro 6.2L LT4 Yes No No No Has the hardware, not active Corvette 6.2L LT1, LT4 Yes Yes No No Auto trans active, manual trans active in ECO only Corvette 6.2L LT5 No No No No Yes No hardware on LT5 Escalade 6.2L L86 Yes Yes No No Suburban/Tahoe/ Yukon 5.3L L83, 6.2L L86 Yes Yes No No Silverado LD/Sierra LD 5.3L L83, 6.2L L86 Yes Yes No No Silverado/Sierra 4.3L LV3 Yes Yes No No Silverado 1500/Sierra 1500 5.3L L82 No Yes Yes No Silverado 1500/Sierra 1500 5.3L L84, 6.2L L87 No No Yes Yes Silverado/Sierra HD 6.6L L8T No No No No No hardware on L8T Express/Savana 4.3L LV1 No No No No No hardware on LV1 Express/Savana 6.6L L8T No No No No No hardware on L8T

There are two ''increased idle 'different functions. One is standard, the other is optional In addition, the ecm will also sometimes adjust idle for alternator charging, ac compressor, high engine temp or in regen to keep exhaust from cooling. (and there may be other reasons....) Elevated Idle is standard on all the dmax's since 2004.5 LLY. It needs to be enabled in settings, but then will automatically engage if the correct conditions are met. It drags the torque converter to create additional load, to warm the transmission as well as the coolant. Since it has automatic engage it is great during cold weather when the truck is started by remote. I find that elevated idle will result in the highest transmission temps my trucks will have doing rural daily driver chores in winter weather. Elevated Idle The engine has a cold temperature high idle feature which elevates the engine idle speed from base idle to 1050 to 1100 rpm when outside temperatures are below 0 °C (32 °F), and the engine coolant temperature is below 65 °C (150 °F). This feature enhances heater performance by raising the engine coolant temperature faster. To turn this feature on or off, see Vehicle Personalization [ Edit to add: My current truck will kick in elevated idle at temps higher than my previous ones. (an LLY and a LML). Despite the 32*F indicated in the manual I find this one will kick in at temps somewhere between 38F and 42F on the dash display] When the engine is started, it will slowly ramp up to the high idle speed after a delay of a few seconds up to approximately two minutes. For this method to work properly there must be no throttle or brake pedal faults. The engine idle speed will return to normal once the following conditions are met: . Engine coolant temperature reaches 65 °C (150 °F). . Air intake temperature reaches 0 °C (32 °F). The high idle speed will be temporarily interrupted and the engine speed will return to normal if any of the following conditions occur: . The brake pedal is applied. . The accelerator pedal is pressed. . The transmission is shifted out of P (Park) or N (Neutral). . Vehicle speed is detected. Once these inputs are removed, the engine idle speed will slowly ramp back up to high idle after the normal delay, if the conditions for engine coolant temperature and air intake temperature are still met. High Idle / Fast Idle The other one is optional, and is operated by the cruise buttons - as in the video above. Sometimes called High idle. Sometimes called Fast Idle. Primary use if to keep accessories (and PTO is equipped) drive running faster. Its'not intended create heat the way the elevated idle does. Fast Idle requires getting into the truck to activate. 2020 dmax manual calls it Fast Idle. Fast Idle Control If equipped, this system can be used to increase the engine idle speed. Fast Idle control will be enabled when the following conditions are met: . The parking brake is set. . The transmission is in P (Park) or N (Neutral). . The vehicle speed is about 0 km/h (0 mph). . The cruise control Set switch is pressed and released for Preset Fast Idle Speed (1200 rpm). Fast Idle control will be disabled when one or more of the following conditions occur: . The cruise control Set switch is pressed and released. See “Cruise Control” in the owner’s manual. . The cruise control Cancel switch is pressed. . The brake pedal is pressed. . The transmission is shifted out of P (Park) or N (Neutral). . The parking brake is released. . The vehicle speed is not 0 km/h (0 mph). Fast/High idle is slightly higher rpm than Elevated idle. I've alway assumed it was to aid in identifying why the truck was not at 'normal' idle. When the truck is in regen, it will idle at higher rpm than normal - but not as high as these two functions.

There's a long list of oils with Dexos1 Gen2 approval. https://www.gmdexos.com/brands/dexos1/index.html

What year was your LML?

1) In general, the tire manufacturer doesn't know what load the tire will see when they manufacture a tire. 2) All tires have a 'load vs inflation pressure' chart (sometimes they are difficult to find) 3) The pressures on the label in the truck are the pressures, from the load/inflation chart, for the tires installed on the vehicle when the vehicle is operating at the trucks maximum rated loads. (for the tire size and ply rating the truck was born with) 4) The max pressure printed on the tire is for the max rated load the tire is capable of -- and that load rating is higher than the trucks rating. 5) Tires typically also have a max pressure - for seating beads. May be different than the max pressure when operating. Too much pressure increases centre wear. Too little pressure increases edge wear. Could get axle weights with it hooked up/loaded and use the chart. https://tirepressure.com/lt-metric-tire-load-inflation-table

Sounds like the truck may have 'Seat Entry Memory' turned off. Vehicle Personalization Settings . To have the Seat Entry Memory movement begin when the vehicle is started, select the Settings menu, then Vehicle, then Seating Position, and then Seat Entry Memory. Select On or Off. See “Seat Entry Memory” later in this section. . To begin Seat Exit Memory movement when the vehicle is turned off and the driver door is opened, or when the vehicle is turned off with the driver door already opened, select the Settings menu, then Vehicle, then Seating Position, and then Seat Exit Memory. Select On or Off. See “Seat Exit Memory” later in this section. Seating Position Touch and the following may display: . Seat Entry Memory . Seat Exit Memory Seat Entry Memory This feature automatically recalls the previously stored 1 or 2 button positions when the ignition is changed from off to on or ACC/ ACCESSORY. See Memory Seats 0 59. Touch Off or On. Seat Exit Memory This feature automatically recalls the previously stored exit button positions when the ignition is changed from on or ACC/ ACCESSORY to off if the driver door is open or opened. See Memory Seats 0 59. Touch Off or On.

For some trucks it may be a faulty condenser: https://gm-techlink.com/?p=13599 Poor Driver’s Side A/C Performance August 31, 2020 The air conditioning may blow warmer on the driver’s side of the vehicle on some 2019-2020 Silverado 1500 and Sierra 1500 models built at the Silao assembly plant (the plant is identified by a G in the 11th position of the VIN). On affected vehicles, the A/C pressures will be lower than normal. For example, the low side may be 15-25 PSI (103-172 kPa) while the high side may be 140-160 PSI (965-1103 kPA). A check of the system for a low refrigerant charge should indicate that the system is full and no leaks should be found. In addition, a temperature test of the refrigerant lines will show both the inlet and outlet lines at the condenser to be similar and very hot. The temperature across the condenser’s cooling fins will be near ambient temperature. The cause of these conditions could be the A/C condenser internally bypassing due to a mispositioned block off plate. If the block off plate is out of position, the refrigerant does not flow through the condenser’s cooling fins. As a result, hot refrigerant entering the condenser bypasses the cooling fins and exits the condenser before the refrigerant is cooled down and returned to a liquid state. If these conditions are found, the A/C condenser (Fig. 22) will need to be replaced. Refer to the appropriate Service Information for A/C condenser replacement. Fig. 22