CCM-0021

Condition
Diagnostic trouble code (DTC) CCM-0021 is stored if the control module registers that the signal from the air quality sensor has a pulse length which is between 48% and 50% of the period.

Condition
- The control module does not permit the recirculation shutter to close in the air quality sensor mode while the fault persists
- No air quality sensor function.

Possible source
- Internal fault in the circuit for the air quality sensor function.

Condition
- Poor air quality in the passenger compartment.