
Diagnostic procedure

No.6 cranks normally but will not start
No.8 engine runs rough/rolling idleMazda 6 Service Manual: Camshaft position (cmp) sensor inspection
Caution
When foreign material such as an iron chip is on the CMP sensor,
it can cause abnormal output from the sensor because of flux turbulence and
adversely affect the engine control. Be sure there is no foreign material on
the CMP sensor when replacing.
Note
Perform the follow ...
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 ...