Control Module HVAC: Description and Operation

Constant Control Relay Module (CCRM).

Constant Control Relay Module:

The CCRM controls the A/C clutch and engine cooling fan motor operation based on signals received from the A/C cycling switch, the A/C pressure transducer, and the Powertrain Control Module (PCM).

The CCRM deactivates the A/C clutch when signaled by the PCM. The A/C clutch is deactivated in this manner under the following conditions:
- Engine start-up.
- Wide Open Throttle (WOT).
- During engine low idle conditions.
- Excessively high engine temperature.