Turn off the circuit breaker to the pump before you attempt to clean it out.
Open the access panel on the holding tank. Remove any debris that may be clogging the pump and preventing the flow, such as diapers or paper towels.
Measure the oil level in the pump motor. The method will depend on the model of pump installed. Some will have a gauge or a level so that you can see how much oil remains. Review the documentation for your pump to determine how to measure and add oil to the motor.
Pull any debris from the outside of the pump that may be clogging it. Examine the inlet valve and any open areas on the pump for bulky material.