If the GP-PWM-30-UL  experiences a battery over voltage (>15.5 VDC) on battery bank 1, the controller will stop operating, and the display will begin to flash with all icons. The controller will resume operating when the voltage drops to a normal level <15.5 VDC. 

Icons Displayed: All symbols

 The controller does not display over voltage on battery 2.

How to Fix It

There's only a number of ways of getting rid of this error:

1. Lower the battery voltage-if you lower the battery voltage back to an acceptable rate (below 15.5v) the error will stop.

The cause could be an unregulated converter, or an alternator from a vehicle that's charging the batteries as well and puts
it above this state.

2. Try a Soft Reset - on the controller. So if it's flashing and you get your voltage down again, below the 15 and a half volt rate and you're able to hold
all four buttons down, it'll stop the flashing from occurring. It's called a soft reset. Sometimes you have to hold the buttons for anywhere between
five to 12 seconds.

The other thing that may stop the flashing is if you've got a too large of a solar bank for too small of a battery bank. The one thing you can
do in that situation is to cover the panels with a piece of cardboard and see if the flashing stops.

If the flashing doesn't stop, the next step would be to try what's called a hard reset on the controller where you disconnect all four wires on the back of the controller, isolate the controller for about a half hour so that slowly discharges and loses its error rate and reconnect the controller battery wires first then solar wires and see if the flashing
continues the does simply disconnect the solar wires on their own and see if it stops. If you get to that stage it may be that there's an issue with the solar controller. Another option to solve the problem would be to add a secondary battery.