- 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: Engine Coolant Temperature Gauge (Without Multi-information Display)
Displays the engine coolant temperature. The white gauge indicates that the engine
coolant temperature is low, and the red gauge indicates that the engine coolant
temperature is high and overheating.
CAUTION
If the engine coolant temperature gauge indicator flashes, there is a possibility
...
Mazda 6 Service Manual: Oil pressure switch inspection
Caution
Water or foreign objects entering the connector can cause poor
connection or corrosion. Be sure not to drop water or foreign objects on the
connector when disconnecting it.
On-vehicle Inspection (harness inspection)
1. Disconnect the negative battery cable.
2. Remove the under ...