How do you get grade to work properly again?

I have a problem with my Garmin Edge 540. I have it since 2023. The grade percentage used to work properly. Then a few times last year when I was riding in heavy rain the numbers were totally messed up. I assumed it was caused by the rain. The Garmin returned to normal later.

Then in 2025 I started riding outside again recently. The grade stat doesn't work anymore. It doesn't matter whether it rains or not. I ride on a flat road and it gives me -2% the whole time. I go slightly uphill on 1% grades and it gives me -1%. I shut down my Edge and it still did the same thing after.

Is there a way to fix this?

0 DanielxcBR 2 months ago

same problem here... My is to wrong edge540 and fr955 compare with my wahoo bolt v2 and hammerhead Karoo (3) from my friend ! In step hill 20% Garmin show 7% but 1 year ago not have any problem wrong gradient only lag !! I wish Garmin priorize that is one of simple important thing that device should do perfectly !!

0 3812952 2 months ago

I tried using a bit of compressed air in the barometer's hole in the back of the unit... It did nothing. I did a ride today on flat terrain and I was like at -2% the whole time.

0 Martin Borsje 1 month ago

Software issue. See as well 840 thread. Uwe IQ Sensible Grade.

0 Peter_Ricc 1 month ago in reply to 3812952

I am also experiencing this with my Edge 1040. A constant -2% grade on what were clearly flat roads. The grade was working well during the summer of 2024, which is around the time Garmin issued a firmware update that addressed the grade lag.

Based on my observation, this issue started sometime after last fall's firmware, as I just took my first 2025 outdoor road bike ride this week.

0 Joemastro 13 days ago

Same issue here. Gradient information is inaccurate. Riding the same hill on my commute which I know is 3-4% it sits at 0% or less.