
Diagnostic procedure

Dtc p0420
Dtc p0480Mazda 6 Service Manual: Nonreturn valve inspection
1. Remove the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.)
2. Siphon the fuel from the fuel tank.
Note
Nonreturn valve is integrated in the fuel tank.
The nonreturn valve is normally closed by the spring force.
3. Verify that the nonreturn valve is closed.
If the nonretu ...
Mazda 6 Service Manual: Dsc hu/cm inspection
1. Remove the battery and battery bracket.
2. Disconnect the DSC HU/CM connector.
3. Connect the SST (49 G066 004) to the DSC HU/CM connector and
harness side connector.
4. Inspect voltage referring the table below.
Terminal Voltage Table (reference value)
(Ignition switch is at ON, and conne ...