gmatx

I was able to figure this out. I was missing a 15 amp fuse on the right side fuse box, in spot F20. Once I put one in my ventilated seats started working again. Yay!

What have you checked on your trailer? I had some faults pop up when I had some water intrude into one of the LED brake lights on my travel trailer. It would happen off and on as the water sloshed around inside the housing. It went away once I replaced the brake light. Also have you tried using a 7 pin trailer brake tester?

2021 GMC Sierra 2500HD AT4 My ventilated seats stopped working a while ago. The manual shows a fuse in the left side instrument panel fuse block, Fuse F6, for "Heated and ventilated seats left/right". That 15A fuse appears fine. The manual also shows a fuse in the right side instrument panel fuse block, Fuse F20, for "Ventilated seats". I am missing that F20 fuse. I don't know if it's always been missing, or if I accidentally removed it when I was hard wiring my dash cam last year. Can someone please tell me if I'm supposed to have the F20 fuse on the right side, and if so what amperage it's supposed to be? Thank you.

I know this is an old post but I'm adding some additional (corrected) information on filling with the correct amount of transmission fluid. The transmission fluid level must be checked while the transmission fluid temperature as displayed on your truck DIC (driver information center) is between 167°F and 176°F. If the fluid is too cold, you will have too much fluid (over-filled), causing "fluid to overflow from the vent tube, possibly causing a fire that may result in serious bodily injury or severe vehicle damage, fluid foaming, or pump cavitation". If the fluid temperature is too hot, you will be under-filled, which will "cause premature component wear or damage". Getting the transmission fluid to the correct level involves heating up the transmission to proper temperature (167°F-176°F), and then removing the pan plug on the bottom of the pan, while the engine is still running and the vehicle is level and in park. If fluid should start to flow out of the pan plug, let it flow until the flow reduces to a drip, then replace the plug. If fluid does not flow out, add additional fluid through the side fill plug until fluid starts to flow out of the pan plug, and then wait for the flow to slow to a drip, and then replace the plug. All of this information and more can be found in the following post, including some instructions/photos taken directly from the GM service manual: https://www.duramaxforum.com/threads/10l1000-servicing.1010029/

I will most likely start changing it myself once I'm out of free oil changes. I think I still get one more more for free, but after that I'll switch to Delvac 1 or Rotella T6.

The service manager just sent me a pic of the oil they used. Mobil Delvac 1300 Super 15W-40 in quart sized bottles, which I'm sure you all know is a very high quality synthetic blend. I know it's more than sufficient for my truck, I just wish the advisor had known they were using a blend when I was there yesterday and asked for full synthetic, and was assured I was getting full synthetic.

I have a fairly new Sierra 2500 HD with Duramax engine. My first oil change was today, provided free by the dealer. I went there hoping they would put in Mobil DELVAC 1 ESP 5W-40 which is fully synthetic. When I asked what they would use, my service advisor said "Dexos". I said are you sure? So he went and asked somebody and came back and said "Delco". I started laughing. Then he said maybe it's "Delo". I looked up Delo -- Chevron Delo 400 comes in Fully Synthetic and in a Synthetic blend. He assured me it was the full synthetic, but I was less than confident. The receipt had part # 88862497. When I looked that up, the parts websites say that it's DELVAC 1300 which I'm 99% sure is a synthetic blend. I'm calling the service manager tomorrow to find out what's what. Maybe if they used a blend I'll get a full refund.

Does anyone know how employee pricing works when it comes to negotiating with a participating dealer? Does negotiating just go out the window for the next month, or are they allowed to sell below that price? In November, my GMC dealer (Texas) agreed to sell me a truck at invoice, less rebates when it comes in. At that time, the GMC cash allowance was $6250, and the dealer was taking off another $4100 to get to invoice price, for a total of $10,350 off of MSRP. Now for December, the GMC cash allowance is $3750, and the Employee Pricing drops it by $6,100, for a total discount of $9,850. Can I still expect my dealer to knock $4,100 (or maybe a smaller amount) off of the price, and give me a tremendous deal, or does employee pricing negate the possibility of any dealer discounts?

To keep the Accessory in ON position for keyless vehicles, put the vehicle in service mode. This may be the solution. It's described in the owner's manual: "Service Mode This power mode is available for service and diagnostics, and to verify the proper operation of the malfunction indicator lamp as may be required for emission inspection purposes. With the vehicle off, and the brake pedal not applied, pressing and holding the ENGINE START/STOP button for more than five seconds will place the vehicle in Service Mode. The instruments and audio systems will operate as they do when the ignition is on, but the vehicle will not be able to be driven. The engine will not start in Service Mode. Press the ENGINE START/STOP button again to turn the ignition off."