- If the DTC exists, diagnose the applicable DTC. (See DTC TABLE.)
- If the DTC does not exist, MIL does not illuminate, and HOLD indicator light flashes, diagnose the applicable symptom troubleshooting. (See SYMPTOM TROUBLESHOOTING ITEM TABLE.)

* :Malfunction indicator lamp (MIL), HOLD indicator light
Automatic transaxle on-board diagnostic functionMazda 6 Service Manual: Pcv valve inspection
1. Disconnect the negative battery cable.
2. Remove the intake maniforld.(see INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
3. Remove the PCV valve.
4. Blow through the valve and verify that air flows as specified.
If not as specified, replace the PCV valve.
Specification
...
Mazda 6 Service Manual: Rear Window Defogger
The rear window defogger clears fog from the rear window.
The ignition must be switched ON to use the defogger.
Press the switch to turn on the rear window defogger. The rear window defogger
operates for about 15 minutes and then turns off automatically.
The indicator light illuminates when the ...