
Diagnostic Procedure

Dtc 18
Dtc 21Mazda 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 ...
Mazda 6 Service Manual: Instrument cluster inspection
Speedometer
Using the input/output check mode
Inspect the speedometer by setting it in the input/output check mode DTC 12.
Using a speedometer tester
1. Adjust the tire air pressure to the specification.
2. Using a speedometer tester, verify that the speedometer indication is
within the allow ...