DTC P2796-12: Electromagnetic Oil Pump Circuit Short to Battery [10/2022 - ]: Description

The oil pump with solenoid assembly is installed inside the automatic transmission assembly.

The oil pump with solenoid assembly operates from the time the engine is stopped due to stop and start control until the vehicle starts moving again in order to ensure oil pressure within the automatic transmission assembly and allow for a smooth start-off.

The engine stop and start ECU supplies power from the backup boost converter to the oil pump with solenoid assembly through Tr1 and performs Tr2 duty control to operate the oil pump with solenoid assembly.

The engine stop and start ECU performs Tr1 and Tr2 control when operating or not operating the oil pump with solenoid assembly and during the preliminary check, and also monitors the EGND terminal to record DTCs.

As a preliminary check, the first time the vehicle speed reaches 2 km/h (1.2 mph) or more on each trip and every time the vehicle speed reaches 2 km/h (1.2 mph) or more after stop and start control is performed, the engine stop and start ECU turns Tr1 ON and checks that there are no malfunctions in the oil pump with solenoid assembly circuit.

The engine stop and start solenoid filter absorbs high-voltage counter-electromotive force generated when the oil pump with solenoid assembly operates.