Auxiliary Climate Control: Other Ford C-MAX II

Cabin Coolant Heater System

The cabin coolant heater system provides warm coolant to the heater core to warm the passenger compartment whenever the DATC module request heat and the vehicle is in a driving mode, remoted started, or doing Cabin Drive-Conditioning.

A SOBDMC controlled cabin coolant heater warms the coolant.

The cabin heater coolant diverter valve allows two modes: Either an isolated coolant loop with cabin coolant heater, heater core, and cabin heater coolant pump or a combined loop of those components along with the engine and other coolant components.

A cabin heater coolant temperature sensor (also known as ECT sensor 2) in the cabin heater system provides the PCM with coolant temperature information.

Cabin Heater Coolant Pump

The cabin heater coolant pump is controlled by the PCM and provides coolant to the cabin coolant heater system while the vehicle is in a driving mode, remoted started, or doing Cabin Drive-Conditioning.

Cabin Coolant Heater

The cabin coolant heater has both low voltage and high voltage electrical connections. The low voltage circuits are used for controlling the unit, while the high voltage circuits are used for heating the coolant. The cabin coolant heater uses electricity, or more accurately, the heat for resistance in electrical circuits to quickly raise the temperature of the coolant to normal operating temperature. The SOBDMC sends power to the cabin coolant heater and controls the PWM circuit to the heater.

Cabin Heater Coolant Temperature Sensor

The PCM monitors the cabin heater coolant temperature sensor (also known as ECT sensor 2) and provides the PCM with coolant temperature information.

Heater Core

The heater core consists of fins and tubes arranged to extract heat from the engine coolant and transfer the heat to air passing through the plenum.

Cabin Heater Coolant Diverter Valve

The default state of the cabin heater coolant diverter valve is de-energized, placing the system in combined loop mode. Coolant flows out of the engine, then back, in the following order

1. cabin heater coolant pump
2. cabin coolant heater
3. cabin heater coolant temperature sensor
4. heater core
5. cabin heater coolant diverter valve
6. thermostat housing
7. main electric water pump

When energized by the PCM , the cabin heater coolant diverter valve places the system into the isolated loop mode. Coolant flows out of the valve, then back, in the following order

1. cabin heater coolant pump
2. cabin coolant heater
3. cabin heater coolant temperature sensor
4. heater core

Possible Causes

1. Low coolant or air in the coolant system
2. ECT sensor 2 (also known as cabin heater coolant temperature sensor)
3. Cabin coolant heater
4. Cabin heater coolant diverter valve
5. Cabin heater coolant pump
6. coolant hose routing

1. Wiring, terminals or connectors
2. ECT sensor 2 (also known as cabin heater coolant temperature sensor)
3. PCM

1. Wiring, terminals or connectors
2. Low coolant or air in the coolant system
3. Cabin heater coolant pump
4. PCM

1. Wiring, terminals or connectors
2. Cabin heater coolant diverter valve
3. PCM

1. Wiring, terminals or connectors
2. Cabin coolant heater
3. SOBDMC

Special Tool(s)/General Equipment

Hose Clamp(s)

Scheme 45

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Scheme 47

Scheme 48

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Scheme 50

1. WARNING: Before beginning any service procedure in this article, refer to Safety Warnings in «GENERAL INFORMATION»(ref-635189) . Failure to follow this instruction may result in serious personal injury. Refer to: «HEALTH AND SAFETY PRECAUTIONS»(ref-635189-S18367805802014070200000) . NOTE: Removal steps in this procedure may contain installation details.
2. Refer to: «HIGH VOLTAGE BATTERY DISCONNECT AND CONNECT - PLUG-IN HYBRID ELECTRIC VEHICLE (PHEV)»(ref-635195-S15098289302014070200000) .
3. Refer to: «JACKING AND LIFTING - OVERVIEW»(ref-635208-S40563097982014070200000) .
4. Refer to: «FENDER SPLASH SHIELD»(ref-635237-S25268650062014070200000) .
5. Use the General Equipment: Hose Clamp(s)
6. Use the General Equipment: Hose Clamp(s)
7. Torque: 89 lb.in (10 Nm)

Special Tool(s)/General Equipment

Hose Clamp(s)

Special Tool(s)/General Equipment

Hose Clamp(s)

Special Tool(s)/General Equipment

Hose Clamp(s)