
Diagnostic procedure

Dtc 21
Dtc 31Mazda 6 Service Manual: Cylinder head gasket
CYLINDER HEAD GASKET REPLACEMENT
Warning
Fuel vapor is hazardous. It can very easily ignite, causing
serious injury and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injuries or death and damage. Fuel ...
Mazda 6 Service Manual: Indication/Indicator Lights
These lights turn on or flash to notify the user of the system operation status
or a system malfunction.
*Some models.
*1 The light turns on when the ignition is switched on for an operation check,
and turns off a few seconds later or when the engine is started. If the light does
not t ...