How to Troubleshoot 21 Error Code on Air Lift Air Bag System

Updated 12/22/2025 | Published 10/20/2024

Question:

My airlift system has an error triangle I go to trouble shoot at it says -21 fast leak. All fuses are good and plugs are tight help

asked by: Dennis

Expert Reply:

Hey Dennis, thanks for reaching out!

The 21 Error Code you're seeing on your Air Lift WirelessONE Compressor System # AL25980 means there is a large leak in the system so checking the fuses and plugs is a good place to start, but you'll need to check all of your fittings and lines to check and see if anything is damaged or loose. Once you fix the leak then you'll have to remove and reinstall the 15A fuse to reset the system.

If you aren't sure where to start, fill a water bottle up with water and dish soap and spray all of your connections and lines down then look for bubbles - any bubbles showing after 30 seconds are an indicator that something needs to be fixed. If you check out pages 21 and 22 for the alternate instructions linked on the product page Air Lift has some other steps to try as well.

expert reply by: Jon G

Jerred H.

12/22/2025

Hey Dennis, did you find the leak in your Air Lift WirelessONE system after checking the fittings and lines? Once you fixed it and reset the fuse, did the error clear up? Your update could make it easier for others troubleshooting the same code.