Back in September I bought a 5th wheel for my GF and I to use occasionally in the Northeast and Mid-Atlantic area. She still has to work for another year or two and can only get up to a week at a time off. A month later I purchased a 2019 Chevy Silverado 3500 HD. My first Diesel.
This past spring, in anticipation of our first trip, I installed a 40 gallon, gravity fed auxiliary fuel tank. I used the recommended install kit and it was an easy process. I tested it by filling the primary tank and put about 10 gallons in the auxiliary. I didn't need the extra fuel to go from Frederick MD to Ocean City but I thought it was pretty cool to travel over 100 miles pulling the 5er before the fuel gauge dropped below full. Anyway, I thought I was good to go.
Last Wednesday I filled both tanks for a 260 mile trip to a COE Lake Campground in West Virginia. Those mountains did a number on my mileage. By the time I pulled into the campground, my fuel gauge had just nudged from the full mark. Again, everything worked fine.
Now for the issue: Yesterday, on the way home I was set with both tanks full and we must have been about an hour into the trip when I noticed my fuel gauge read empty! The low fuel warning light wasn't on just the gauge was as low as it can go. We pulled into a rest area and checked the auxiliary tank and it was full. I also shut off and restarted the truck but the fuel gauge returned to empty. With nothing more to do we continued our journey home.
About 100 miles from home the check engine light came on and approximately 50 miles from home I noticed the fuel gauge read full again! This morning, the check engine light remains on (of course) and the fuel gauge is just a bump below full.
My email from OnStar reads: "An issue with the Engine and Transmission System in your 2019 Chevrolet Silverado has been detected. Please service your vehicle within 7 days."
I have a Thursday morning appointment at the dealer. In the meantime, I'd appreciate any thoughts on what may have happened to make the gauge hiccup.
Thank you,
Al