This error can occur on any truck, however is it mostly noticeable on internationals. When drivers first start the truck, and air pressure is low, and they attempt to shift the truck into gear, they will get an error message saying “Transmission Air Supply Low”. There is no issue with the truck, or the transmission. Drivers just need to wait for the truck to fully air up (Until the air compressor shuts off and they hear the air exhaust) to be able to shift the truck.