Reply To: P2404 code on 2018 subaru crosstrek

[Dave Tidman]

I’m not sure if you have seen this, but it may help

http://www.sucross.com/dtc_p2404_evap_system_leak_detection_pump_sense_circuit_range_performance-1929.html

The code is because the ecm can’t determine if the leak detection pump is running. It is most likely the pump or the wiring between the ecm and the pump. A bidirectional scan tool would be helpful, but probably not available to you.