Hello everyone! I am a forum newbie but I wanted to get some advice and insight on my new 2023 GLC. I had it a little over 3 months with about 2700 miles (I know I drive a lot) and I love the car, however out of the blue I am having issues. When first getting the car I had an issue where the rear camera randomly disabled but the next day it worked him and has been working since. Also, a few times my CarPlay randomly freezes but it seems to work again. But recently I have been having issues with the fuel reading on the car. In late Sept I had a low fuel warning which was accurate as I haven’t refueled in about a week. I went to my local has station and refueled and no problem and filled it completely. About two hours later, my check engine light randomly came on and my fuel read 0 on both the app and the dashboard. I towed the car to the dealer and was without a car for 10 days and got it back about 4 days ago. For two days after everything was fine and I noticed my fuel reading went down significantly like 260 to 199 and at half a tank. I thought it was quick but maybe it was accurate. On my way from work on the highway I realized my fuel level is increasing instead of decreasing. It went from 199 in the am to 370 by 3:00pm and reads 100% on the app. Its impossible for this to be accurate as I have been driving with and have not refueled. For the past few days it is still reading 100%. This will be my second time taking it back to the dealer. Any idea on what could be happening. I am scared my car can need fuel and I’m not getting warning. I feel as if my vehicle system is not syncing. Also today by app keep notifying me that my alarm is enabled and is going off but it was in my garage. I am scared I may have a lemon on my hands and unsure of what to tell the dealer.

 

I am not sure if it is related but there is a fuel pump recall, not sure if your vehicle is affected, your SA will now though after looking up your VIN in the VMI.

 

This won’t solve your problem but you can assuage your anxiety by calculating your remaining fuel by assuming you get 25 mpg (ymmv). Assuming you have at least 17 gallons after filling, you should be able to drive 400 miles with a 25 mile reserve.
I apologize if you find this insulting, but I often forget the simplest strategies and need reminding.

 

I can't explain, or don't understand your "zero reading on the app and car."

But if you're talking about the "miles remaining" estimate above the fuel gauge, it's based on your recent driving habits.

Example: you've been driving in town, heavy traffic, maybe getting 20 mpg. You fill up and head out on a trip, where you are getting 30.
Your estimate will initially show (let's say) 13 gal X 20mph - 260 miles. 5 miles later, now getting 30, the estimate will show @ 390.
Nothing is amiss there.

The app display sometimes has a lag or delay, but the onboard fuel gauge dropping to zero is baffling.

 

Thank you all so much for the information and apologies for any confusion or unclarity. Two weeks ago - about 2 hours after filling the tank to full, my check engine light came on and my miles to empty on my dashboard was 0. On the app it also says my fuel level was low. Because I filled the tank and drove about 4/5 miles I knew it was an issue because it was impossible for the fuel level to be low after resuming full and driving 4/5 miles. I had the car towed to the nearest dealer and they kept the car for 10 days- I just received it last week in 10/4 where the miles to empty read about 277 miles to empty.. Between picking the car up on Wednesday after to Friday morning I may have drove about 80 miles and the mileage to empty read 199. Later on Friday afternoon the miles to empty increased to 377. I drove about another 70 miles for the next few days and it the miles to empty either stays at a certain range or continues to increase. Currently it says I have a 99% fuel level which is impossible given the 100+ I’ve driven since I received the car back last Wednesday 10/4. I have not refueled yet. When I brought the car to the dealer two weeks ago I was at 2970 miles,currently I’m at 3010 so a 99% rating seems very inaccurate. I’m currently back at the dealer with the hopes of a solution or explanation. My VIN is saying there is not a recall.


When I brought it to the dealer about two hours after I filled the gas tank

What my car currently reads. I have not refueled the car at all.

 

Assuming you don’t ever overfill the tank and do get the gas cap tight, I agree (as, I am sure, do we all) you have an electronic issue requiring a dealer to address. If it were me, I would continue to be confident enough to drive the car because you did not report any driveability isues. Just keep track of your miles driven (I use the consumption screen “From Reset” to monitor miles until the dealer can take the car for repair.
Pre computers, I would have looked at the actual guage first and the gas tank sender second. With our cars, however, who knows where they put that particular computer! In any case, It would defy reason for the engine ECU to depend on a digital display unit or even a tank level sensor.

 

Thank you all for the great advice. I reset the trip and refueled my car until full - which was a little over 10 gallons - so there is definitely an issue with the fuel reading. Once I filled the mileage range increased slightly but then I started to see the fuel level percentage go down. Now I am having the opposite problem. After refueling I have driven approx 65 miles and now my fuel percentage is 57% on the app and almost at the 1/2 mark. So today I tried to refuel to see what’s going on and about 2.5 gallons in I had a full tank. My tank is completely filled and my fuel range is still at 56%. But what is a bit concerning to me is how quickly the fuel range is decreasing rapidly while I’m in the vehicle. Yesterday while driving mostly on the freeway for about 16 miles my fuel level dropped from 303 to 234 miles left on a 31 min drive that averages 27mpg. By the time I completed my day which was an extra 5 miles averaging 24mpg the fuel level dropped to 211 miles remaining. While I was idle in my car for about 2 minutes it continued to drop to 208 miles remaining. Today while driving 5 miles in the city at 24mph my fuel level is now at 204 miles remaining and 57%. As I mentioned I refueled and the fuel range continues to go down rapidly. I have taken it to the dealer about 3 times now and still am having the issue. Any suggestions on what I can do or should I utilize the lemon law and classify it as a lemon.

 

Regarding a lemon law: Have you followed your dealer's suggestions regarding this matter?

 

All that sounds normal.

Try heading out on a 55mph road, driving gently for a few miles. Your "indicated range" should increase, even though your gallons remaining is decreasing.

"Range" is based on your current and most recent right foot action.
Without that part of troubleshooting, we (or the dealer) don't know if there's even a problem.