Possible causes

– Faulty Engine control Module (ECM)
– Engine control Module(ECM) harness is open or shorted
– Engine control Module (ECM) cicuit poor electricl connection
– Low battery voltage

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0600 SUBARU Description

The PCM did not detect communication between modules

SUBARU Technical Service Bulletins for P0600 code