This means there is a fault that could give you incorrect information or the PDC's battery is dead. Here is what you should do if your PDC is not working.
- Signal to your buddy, indicate you have a broken PDC, and follow these ascent procedures.
- Stop at 10 meters/33 feet for 2 minutes if you are below 10 meters/33 feet.
- Stop at 5 meters/15 feet for 15 minutes or until your SPG reads 50 bar/750 psi and then surface normally.
- Ask your buddy to indicate the depths.