Diagnostic procedure
Mazda 6 Service Manual: No.4 air intake mode does not change
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminal ...
Mazda 6 Service Manual: Immobilizer System
The immobilizer system allows the engine to start only with a key the system
recognizes.
If someone attempts to start the engine with an unrecognized key, the engine
will not start, thereby helping to prevent vehicle theft.
If you have a problem with the immobilizer system or the key, consult ...