Integrated Control Relay Module: Description and Operation

OVERVIEW
The Constant Control Relay Module (CCRM) interfaces with the Electronic EC system to provide control for the cooling fan and A/C clutch. The CCRM may also contain the Fuel Pump Relay for fuel pump control and the Electronic EC Power Relay which provides Vehicle Power (VPWR) to the Powertrain Control Module (PCM) and the Electronic EC system. Two separate High Speed Fan Control relays may be used because of the high current required for the high speed fans. If any of the internal components of the CCRM fail, the entire unit must be replaced. The descriptions of the specific CCRM functions, as well as the Dual Function A/C Pressure Switch, the Fuel Pump Monitor and the Fan Monitor circuits, are found under the individual hardware - PCM inputs and outputs in this section. For more information on specific CCRM content, refer to the vehicle specific Electrical and Vacuum Troubleshooting Manual (EVTM).


HEATING AND AIR CONDITIONING
The constant control relay module (CCRM) is located on the radiator support it is used to cycle the engine cooling fan on whenever the A/C compressor (19703) is operating. CCRM incorporates circuit control provisions for various engine functions as well as for the fan motor (8C607) and the A/C clutch field coil (2967). CCRM energizes the fan motor when the engine coolant temperature reaches approximately 105°C (221°F). If an A/C function is chosen, the A/C clutch field coil will energize only when the fan motor is operating. The CCRM will engage or disengage the fan if the A/C is on and vehicle speed does not provide enough natural airflow and engine cooling fan motor starts running at or below 69 km/h (43 mph) and disengages at 77 km/h (48 mph).

NOTE: The following conditions may cause the A/C compressor to disengage due to the constant control relay module: wide open throttle (WOT), very high or too low engine rpm, engine cranking high engine coolant temperature of 118°C (245°F) A low or no refrigerant condition will also prevent the A/C compressor from engaging.


COOLING SYSTEM

WARNING: Disconnect the cooling fan motor prior to performing any underhood service since the cooling fan motor could cycle if the ignition switch is left in the ON position even though the engine is not running.

NOTE: Cooling fan motor will not cycle with A/C clutch (2884). The cooling fan motor will come on when A/C switch is turned ON.

The cooling fan motor is controlled during vehicle operation by the Constant Control Relay Module (CCRM)(12B581) and powertrain control module (PCM)(12A650), which will energize the cooling fan motor to run at low speed under the following conditions: if engine temperature is higher than normal. Cooling fan motor starts running at 106°C (222°F) and stops running at 101°C (214°F), if A/C is on and vehicle speed does not provide enough natural airflow. Cooling fan motor starts running at speeds at or below 69 km/h (43 mph) and stops running at 77 km/h (48mph).

Cooling fan motor will run at high speed: if engine temperature is higher than desirable and cooling fan motor has been operating at a low speed. Engine temperature at 109°C (228°F) and stops running at 105°C (220°F).