
Diagnostic procedure


Dtc b1869, b1870
Dtc b1877, b1878, b1879, b1885Mazda 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: Mass air flow (maf) sensor inspection
Voltage Inspection
Note
Perform the following inspection only when directed.
1. Visually inspect for the following on the MAF sensor.
Damage
Cracks
Terminal bends
Terminal rust
- If any of the above are found, replace the MAF sensor.
- If the MAF PID value is out of specifi ...