- 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: Oil pressure switch removal/installation
Warning
When the transaxle and ATF are hot, they can badly burn. Turn off
the engine and wait untill they are cool before replacing ATF.
1. Disconnect the negative battery cable.
2. Remove the under cover.
3. Disconnect the cord assembly connector.
4. Remove the oil pressure switch.
...
Mazda 6 Service Manual: Multiplex communication system
Outline
In case the controller area network (CAN) system is malfunctioning, read
the DTCs of the following modules, using the SST (WDS or equivalent) to
determine the malfunctioning system.
- PCM
- DSC HU/CM (with DSC)
- ABS (ABS/TCS) HU/CM (with ABS (ABS/TCS)
- Instrument clus ...