
Diagnostic Procedure

Dtc 18
Dtc 21Mazda 6 Service Manual: Engine control system operation inspection
Main Relay Operation Inspection
Verify that the main relay clicks when the ignition switch is turned to ON
position and off.
If there is no operation sound, inspect the following.
- Main relay (See RELAY INSPECTION.)
- Harness and connector between ignition switch and main relay termi ...
Mazda 6 Service Manual: Intake air temperature (iat) sensor inspection
Resistance Inspection
Note
Perform the following inspection only when directed.
1. Disconnect MAF/IAT sensor.
2. Measure the resistance between the MAF/IAT sensor terminals D and E using
an ohmmeter.
If not as specified, replace the MAF/IAT sensor.
If the MAF/IAT sensor is okay, but ...