Contents Wiring diagrams Section: Automatic HVAC System All sections

HVAC Control System: Other Mercury Mariner II

Automatic HVAC System 26 illustrations ~5358 words

Material

ItemSpecificationFill Capacity
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B
R-134a Refrigerant YN-19 (US); CYN-16-P or CYN-16-R (Canada)WSH-M17B19-A
Silicone Gasket and Sealant TA-30WSE-M4G323-A4

Material

Thermal Protection Switch (Hybrid Only)

Under high air conditioning load conditions, the A/C compressor temperature may get hot enough to trigger the compressor thermal protection switch which will disengage the A/C compressor clutch. The thermal protection switch is located in the A/C compressor housing, near the discharge port and is wired in series with the A/C clutch field coil. When refrigerant discharge temperatures heat the switch to 115°C (239°F), the switch will open and disengage the compressor, but no PCM DTCs will be set. The switch will close once the temperature cools to approximately 105°C (221°F). If the switch were to stick open, it would remain open at room temperature.

A/C Condenser

Note. Installation of a new receiver/drier is not required when repairing the air conditioning system, except when there is physical evidence of contamination from a failed A/C compressor or damage to the receiver/drier.

The A/C condenser is an aluminum fin-and-micro-channel design heat exchanger located in front of the vehicle radiator. It cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat and by condensing gas to liquid refrigerant as it is cooled.

On 2.3L or 3.0L (4V) vehicles equipped with an automatic transmission, the top portion of the condenser is partitioned from the refrigerant system and is used for transmission fluid cooling.

Evaporator Core

Note. Installation of a new receiver/drier is not required when repairing the air conditioning system, except when there is physical evidence of contamination from a failed A/C compressor or damage to the receiver/drier.

Note. A second (auxiliary) evaporator core is used for HVTB cooling on hybrid vehicles. For information concerning the auxiliary evaporator core, refer to AUXILIARY CLIMATE CONTROL - HYBRID article.

The evaporator core is an aluminum plate/fin-type and is located in the heater core and evaporator core housing. A mixture of liquid refrigerant and oil enters the bottom of the evaporator core through the evaporator core inlet tube and continues out of the evaporator core through the evaporator core outlet tube as a vapor. During A/C compressor operation, airflow from the blower motor is cooled and dehumidified as it flows through the evaporator core fins.

Thermostatic Expansion Valve (TXV)

Note. Installation of a new receiver/drier is not required when repairing the air conditioning system, except when there is physical evidence of contamination from a failed A/C compressor or damage to the receiver/drier.

Note. A second (auxiliary) TXV is used for HVTB cooling on hybrid vehicles. For information concerning the auxiliary TXV, refer to AUXILIARY CLIMATE CONTROL - HYBRID article.

The TXV is located at the evaporator core inlet and outlet tubes at the dash panel at the rear of the engine compartment. The TXV provides a restriction to the flow of refrigerant from the high-pressure side of the refrigerant system and separates the low-pressure and high-pressure sides of the refrigerant system. Refrigerant entering and exiting the evaporator core passes through the TXV through 2 separate flow paths. An internal temperature sensing bulb senses the temperature of the refrigerant flowing out of the evaporator core and adjusts an internal pin-type valve to meter the refrigerant flow into the evaporator core. The internal pin-type valve decreases the amount of refrigerant entering the evaporator core at lower temperatures and increases the amount of refrigerant entering the evaporator core at higher temperatures.

Receiver/Drier

Note. Installation of a new receiver/drier is not required when repairing the air conditioning system, except when there is physical evidence of contamination from a failed A/C compressor or damage to the receiver/drier.

The receiver/drier is mounted to the right of the radiator support for 2.3L or 3.0L (4V) vehicles, or at the RH shock tower for hybrid vehicles. It stores high-pressure liquid after it leaves the condenser core. A desiccant cartridge mounted inside the receiver/drier removes any retained moisture from the refrigerant.

Evaporator Discharge Air Temperature Sensor

Note. A second (auxiliary) evaporator discharge air temperature sensor is used for the auxiliary evaporator core on hybrid vehicles. For information concerning the auxiliary evaporator discharge air temperature sensor, refer to AUXILIARY CLIMATE CONTROL - HYBRID article.

The evaporator discharge air temperature sensor contains a thermistor. The resistance of this thermistor varies by a specific amount based on the evaporator discharge air temperature. The dual-zone EATC or EMTC module measures a voltage ratio between the reference voltage it supplies to the sensor and the sensor return voltage to determine this resistance and the associated discharge air temperature.

The evaporator discharge air temperature sensor maintains evaporator core temperature and prevents icing of the evaporator core. It does this by signaling the HVAC module to switch off the A/C request signal to the instrument cluster on 2.3L or 3.0L (4V) vehicles, or signaling the PCM to cycle the A/C compressor off when the evaporator discharge air temperature sensor reading falls below acceptable levels. The A/C request or A/C compressor will be switched back on when the evaporator temperature rises above acceptable levels.

On hybrid vehicles, the A/C compressor will continue to run and the passenger zone valve will be closed by the PCM if the evaporator discharge air temperature sensor is reading a temperature below acceptable levels, but the TBCM is requesting A/C operation for HVTB cooling. This allows continued refrigerant flow to the auxiliary evaporator core while allowing the front (main) evaporator core to warm to acceptable levels.

The evaporator discharge air temperature sensor is located on the heater core and evaporator core housing behind the glove compartment.

Scheme 160

Scheme 160: Dual-Function Pressure Switch
ItemPart NumberDescription
1Dual-function pressure switch electrical connector (part of 14290)
219D594Dual-function pressure switch
319D701Dual-function pressure switch Schrader-type valve
419E889O-ring seal

The dual-function pressure switch is located on the receiver drier and includes 2 separate sets of contacts that are opened at 2 different pressures.

The first set of contacts in the dual-function pressure switch is used to interrupt A/C compressor operation in the event of excessively high discharge pressure in the high-pressure side of the refrigerant system. The PCM monitors the first set of contacts in the dual-function pressure switch in-series with the low-charge protection switch. When the contacts are open, the PCM will disengage the A/C compressor clutch.

The second set of contacts in the dual-function pressure switch is used by the PCM to engage the high-speed cooling fan. The PCM monitors the second set of contacts through the A/C pressure (ACP) circuit. When the A/C pressure rises above a preset level, the second set of contacts will close and the high-speed cooling fan will be engaged.

The dual-function pressure switch is installed on a Schrader-type valve core fitting on the receiver/drier. It is not necessary to recover the refrigerant to remove the dual-function pressure switch.

Scheme 161

Scheme 161: Low-Charge Protection Switch
ItemPart NumberDescription
1Low-charge protection switch electrical connector (part of 14290)
219E561Low-charge protection switch
319D701Low-charge protection switch Schrader-type valve
419E889O-ring seal

The low-charge protection switch is installed on the evaporator outlet line to cycle the A/C compressor off in the event of a low refrigerant charge. The PCM monitors the low-charge protection switch in-series with the dual-function pressure switch. When the low-side pressure drops below acceptable levels, the low-charge protection switch contacts open. When the low-charge protection switch contacts are open, the PCM will disengage the A/C compressor clutch.

The low-charge protection switch is installed on a Schrader-type valve core fitting on the evaporator outlet line. It is not necessary to recover the refrigerant to remove the low-charge protection switch.

Passenger Zone Valve (Hybrid Only)

The passenger zone valve is a solenoid-type valve used on hybrid vehicles to isolate the front (main) evaporator core from the refrigerant system when the A/C compressor is operating for high-voltage traction battery (HVTB) cooling and A/C operation has not been selected for the passenger compartment. When A/C operation has been selected for the passenger compartment, the passenger zone valve will also be closed to prevent freezing of the front evaporator core if the front evaporator discharge air temperature sensor indicates that the front evaporator temperature has fallen below acceptable levels, while the auxiliary evaporator discharge air temperature sensor is reading within acceptable levels. This is done to prevent the A/C compressor from having to be cycled off when HVTB cooling is still required.

When voltage is applied to the passenger zone valve, it will be in the open state. When voltage is removed, the passenger zone valve will be in the closed state.

The passenger zone valve will only be in either the fully open or the fully closed state and cannot be partially opened.

The passenger zone valve is mounted at the top of the RH shock tower.

Battery Zone Valve (Hybrid Only)

The battery zone valve is a solenoid-type valve used by the PCM on hybrid vehicles to isolate the auxiliary evaporator core from the refrigerant system, when the A/C compressor is operating for passenger compartment cooling and A/C operation has not been requested for HVTB cooling. When A/C operation is requested for HVTB cooling, the battery zone valve will also be closed to prevent freezing of the auxiliary evaporator core if the auxiliary evaporator discharge air temperature sensor indicates that the auxiliary evaporator temperature has fallen below acceptable levels, while the front (main) evaporator discharge air temperature sensor is reading within acceptable levels. This is done to prevent the A/C compressor from having to be cycled off when passenger compartment cooling is still required.

The battery zone valve will periodically be briefly opened during front (main) A/C operation for system maintenance. When A/C operation is not requested, the battery zone valve is closed.

When voltage is applied to the battery zone valve, it will be in the open state. When voltage is removed, the battery zone valve will be in the closed state. The battery zone valve will only be in the fully open or the fully closed state and cannot be partially opened.

The battery zone valve is mounted to the bottom of the auxiliary climate control housing. Refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS - HYBRID article.

Service Gauge Port Valves

The high-pressure service gauge port valve is located on the receiver/drier inlet line.

The low-pressure service gauge port valve is located on the evaporator outlet line.

Note. Different valve cores are used for different engine applications. Use only the valve core listed in the Ford Master Parts Catalog for the vehicle and fitting being serviced.

Scheme 162

Scheme 162: Service Gauge Port Valves
ItemPart NumberDescription
119D702Low-pressure service gauge port valve cap
2Low-pressure service gauge port valve (part of 19867 for 2.3L or 3.0L [4V]) (part of 19D850 for hybrid)
319D701Low-pressure Schrader-type valve
419D701High-pressure Schrader-type valve
5High-pressure service gauge port valve (part of 19C836 for 2.3L or 3.0L [4V]) (part of 19835 for hybrid)
619D702High-pressure service gauge port valve cap

The fitting is an integral part of the refrigerant line or component.

  1. Special couplings are required for both the high-side and low-side service gauge ports.
  2. A very small amount of leakage will always be detectable around the Schrader-type valve with the service gauge port valve cap removed, and is considered normal. A new Schrader-type valve core can be installed if the seal leaks excessively.
  3. The service gauge port valve caps are used as primary seals in the refrigerant system to prevent leakage through the Schrader-type valves from reaching the atmosphere. Always install and tighten the A/C service gauge port valve caps to the correct torque after they are removed.

Refrigerant System Dye

Fluorescent refrigerant system dye is added to the refrigerant system at the factory to assist in refrigerant system leak diagnosis using a Rotunda approved ultraviolet blacklight. It is not necessary to add additional dye to the refrigerant system before diagnosing leaks, even if a significant amount of refrigerant has been removed from the system. Replacement receiver/driers are shipped with a fluorescent dye "wafer" included in the desiccant cartridge, which will dissolve after approximately 30 minutes of continued A/C operation. It is not necessary to add dye after flushing or filtering the refrigerant system because a new receiver/drier is installed as part of the flushing or filtering procedure. Additional refrigerant system dye should only be added if more than 50 percent of the refrigerant system lubricant capacity has been lost due to a fitting separation or hose rupture. Refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS article.

Refrigerant Line Fittings

CAUTIONUse only a plastic or nonmetallic tool for removing O-ring seals and gasket seals from the refrigerant line fittings. Use of a metallic tool will create scratches on the sealing surface of the fitting that can result in refrigerant system leaks.

Whenever a refrigerant line fitting is disconnected, the fitting must be cleaned of any foreign material and new O-ring seals and/or gasket seals must be installed. Use only the O-ring seals and gasket seals specified in the Ford Master Parts Catalog.

If a refrigerant system line fitting must remain disconnected for an extended period of time, it should be capped to avoid contamination of the refrigerant system.

Air Distribution

Note. A cabin air filter is available for this vehicle as a dealer installed accessory. The accessory cabin air filter will be located in the air inlet under the RH side of the cowl panel grille, if installed.

There are 2 sources of air available to the air distribution system

  1. Outside air
  2. Recirculated air

Recirculated air is always used when the HVAC module is set to the MAX A/C mode on vehicles equipped with electronic manual temperature control (EMTC) and can be selected in any mode except DEFROST. Vehicles equipped with dual-zone electronic automatic temperature control (EATC) use recirculated air only when the RECIRC function is selected in any mode other than DEFROST, or when required by the HVAC module in the AUTOMATIC mode.

Air distribution within the vehicle is determined by the airflow mode selected, or by the dual-zone EATC system in the AUTO mode. The air distribution mode on vehicles equipped with dual-zone EATC can be overridden by the driver if desired. Airflow mode control doors are used to direct airflow within the heater core and evaporator core housing. Electric mode door actuators are used to position the airflow mode doors and air inlet mode door.

Vehicles equipped with dual-zone EATC use 2 separate temperature blend doors. This allows individual temperature settings to be selected for the RH and LH air outlets. The airflow mode doors are not partitioned for separate RH and LH airflow positions. Therefore, the airflow mode will always remain similar for the RH and LH sides of the vehicle regardless of the temperatures selected.

Air enters the passenger compartment from the following outlets

  1. Instrument panel registers
  2. Floor duct outlets
  3. Windshield defroster
  4. Side window demisters
  5. Rear footwell duct
  6. Center console registers

Passenger compartment air is exhausted from the vehicle through open windows or body air vents.

Control Components

Two climate control systems are available

  1. Electronic manual temperature control (EMTC)
  2. Dual-zone electronic automatic temperature control (EATC)

Refer to the appropriate heading below for information concerning each system.

Electronic Manual Temperature Control (EMTC)

Note. EMTC is not available on hybrid vehicles.

The HVAC module allows you to select the following

  1. Air inlet source (outside or recirculated)
  2. Blower motor speed
  3. Discharge air temperature (temperature blend)
  4. Discharge air location (defrost, panel, floor, panel/floor, defrost/floor)
  5. A/C compressor operation
  6. Rear window defroster operation
  7. Heated seat operation (if equipped)

Control System Inputs

The temperature control selector setting determines air temperature. Movement of the temperature display from COOL (blue) to WARM (red) causes a corresponding movement of the temperature blend door and determines the discharge air temperature that the air distribution system will maintain. The temperature control selector is an integral part of the HVAC module and cannot be installed separately. The temperature selector knob is removable and can be installed separately.

The airflow mode setting determines air discharge location. Depressing each airflow mode selector button causes a corresponding movement of the airflow mode doors and determines the air discharge location. The airflow mode selector buttons are an integral part of the HVAC module and cannot be installed separately.

The A/C request button determines A/C compressor operation, except when the airflow mode selector is in the OFF, MAX A/C or DEFROST mode. The A/C request button is an integral part of the HVAC module and cannot be installed separately.

The recirculated air request button can select recirculated air in any mode except DEFROST, and fresh air in any mode except MAX A/C or OFF. The recirculated air request button is an integral part of the HVAC module and cannot be installed separately.

The rear defog button signals activation of the heated backlight. The rear defog button is an integral part of the HVAC module and cannot be installed separately.

The blower motor speed switch is mounted in the HVAC module and controls blower motor speed by adding or bypassing resistors in the blower motor resistor in all modes except OFF. The blower motor switch knob is removable and can be installed separately.

Control System Outputs

The EMTC system has 4 system outputs.

Blower Motor Speed

The blower motor speed switch varies the blower motor ground circuit resistance by adding or bypassing series resistance in the blower motor resistor. Increased resistance will lower the blower motor speed, and lowered resistance will increase blower motor speed. When the blower motor is in the HI (4) position, the blower motor resistor is bypassed.

The blower motor resistor is located on the heater core and evaporator core housing behind the glove compartment.

Temperature Blend Door Position

The temperature blend door actuator moves the temperature blend door on command from the HVAC module.

The temperature blend door actuator contains a reversible electric motor and a potentiometer. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal return circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal returned to the HVAC module from the contact wiper indicates the position of the temperature blend door. The HVAC module drives the actuator motor in whichever direction is necessary to make the actuator contact wiper voltage agree with the expected HVAC module value. The expected value is set by the vehicle occupants using the temperature selector knob.

The temperature blend door actuator is mounted to the heater core and evaporator core housing.

Airflow Mode Door Position

The airflow mode door actuator uses a cam and lever assembly to position the airflow mode doors on command from the HVAC module. The mode door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC module to monitor the position of the airflow mode doors. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal return circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal returned to the HVAC module from the contact wiper indicates the position of the airflow mode doors. The expected HVAC value is set by the vehicle occupants using the mode selector buttons.

The airflow mode door actuator is mounted to the plenum chamber to the right of the accelerator pedal.

Air Inlet Mode Door Position

The air inlet mode door actuator moves the air inlet door between the fresh and RECIRC positions on command from the HVAC module. The air inlet mode door actuator is driven to, and will automatically stop at, the full RECIRC or full fresh air inlet position and does not require a potentiometer circuit to monitor its position. The airflow mode door does not stop at any point between the RECIRC or fresh air inlet position.

The air inlet mode door actuator is mounted to dash panel side of the air inlet duct.

Electronic Automatic Temperature Control (EATC)

The HVAC module analyzes input from the following major sources

  1. Temperature, airflow mode, blower, A/C and RECIRC selection (made by the vehicle occupants)
  2. ECON button (hybrid only)
  3. In-vehicle temperature sensor (2.3L or 3.0L)
  4. In-vehicle temperature and humidity sensor (hybrid only)
  5. Ambient temperature sensor
  6. Sunload sensor (solar radiation sensor)
  7. Evaporator discharge air temperature sensor
  8. Vehicle speed
  9. Engine coolant temperature

Using these inputs, the HVAC module determines the correct conditions for the following outputs

  1. A/C compressor ON/OFF request
  2. Blower motor speed
  3. Temperature blend door position
  4. Airflow mode door position
  5. Air inlet door position

The dual-zone EATC system has 4 control system inputs.

HVAC Module

The HVAC module provides an interface for the vehicle occupants to control the climate control system, or automatically controls the climate control system in the AUTO mode. The HVAC module uses the front display interface module (FDIM) for displaying set temperature, airflow direction, blower speed and DTCs. An on-board diagnostic (OBD) feature is incorporated to supply the technician with DTCs. These DTCs help direct the technician to the inoperative component.

In-Vehicle Temperature Sensor - 2.3L or 3.0L (4V)

The in-vehicle temperature sensor contains a thermistor, which measures the in-vehicle air temperature and sends that reading to the HVAC module. An aspirator hose is connected between the heater core and evaporator core housing and the in-vehicle temperature sensor. The aspirator hose uses airflow through the heater core and evaporator core housing to create a Venturi-type suction to draw in vehicle air through the in-vehicle temperature sensor (across the thermistor).

The in-vehicle temperature sensor is mounted to the RH lower portion of the instrument cluster finish panel.

In-Vehicle Temperature and Humidity Sensor - Hybrid

The in-vehicle temperature and humidity sensor contains 2 thermistors, which separately measure the in-vehicle air temperature and humidity and send those readings to the HVAC module. An aspirator hose and elbow is connected between the heater core and evaporator core housing and the in-vehicle temperature and humidity sensor. The aspirator hose uses airflow from the heater core and evaporator core housing air stream to create a Venturi-type suction to draw in vehicle air through the in-vehicle temperature sensor and across the thermistors.

The in-vehicle temperature and humidity sensor is mounted to the RH lower portion of the instrument cluster finish panel.

Sunload Sensor (Solar Radiation Sensor)

The solar radiation sensor supplies information to the HVAC module indicating sunload strength, and (to an extent) direction. The solar radiation sensor is located on the center of the instrument panel at the base of the windshield.

Ambient Temperature Sensor

The ambient temperature sensor signal is received by the HVAC module and indicates the outside air temperature. The ambient temperature sensor is located in front of the radiator on the bottom of the bumper beam.

The ambient temperature sensor signal is not the sole factor considered by the HVAC module for the outside air temperature display. Therefore, the ambient temperature PID monitored with a scan tool may not exactly match the HVAC module display. For information regarding the HVAC module outside air temperature display, refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS article.

The EATC system has 4 control system outputs. When operating in AUTO mode, the control system outputs will be automatically adjusted by the HVAC module.

Note. Each of the 4 control system outputs may be overridden by the passenger if desired.

The blower motor speed control controls the blower motor speed by converting low power signals from the HVAC module to a high-current, variable ground feed for the blower motor. A delay function is used to provide a gradual increase or decrease in blower motor speed under all conditions.

The dual-zone EATC system uses 2 temperature blend door actuators to control 2 separate temperature blend doors. The temperature blend doors independently vary the LH side and RH side temperature settings, as desired. The temperature blend door actuators each contain a reversible electric motor and a potentiometer. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal return circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal returned to the HVAC module from the contact wiper indicates the position of the temperature blend door. The HVAC module drives the actuator motor in whichever direction is necessary to make the actuator contact wiper voltage agree with the expected HVAC module contact wiper voltage value, as determined by the control algorithm.

The temperature blend door actuators are mounted to the heater core and evaporator core housing.

The airflow mode door actuator uses a cam and lever assembly to position the airflow mode doors on command from the HVAC module. The mode door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC module to monitor the position of the airflow mode doors. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal return circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal returned to the HVAC module from the contact wiper indicates the position of the airflow mode doors. The HVAC module drives the actuator motor in whichever direction is necessary to make the actuator contact wiper voltage agree with the expected contact wiper voltage value, as determined by the control algorithm.

The airflow mode door actuator is mounted to the plenum chamber to the right of the accelerator pedal.

Air Inlet Mode Door Actuator

The air inlet mode door actuator moves the air inlet door between the fresh and RECIRC positions on command from the HVAC module. The air inlet mode door actuator is driven to, and will automatically stop at, the full RECIRC or full fresh air inlet position and does not require a potentiometer circuit to monitor its position. The airflow mode door does not stop at any point between the RECIRC or fresh air inlet position.

The air inlet mode door actuator is mounted to dash panel side of the air inlet duct.

Heating and Ventilation

The heating and ventilation system has the following features

  1. Controls the temperature and, during A/C operation, reduces the relative humidity of the air inside the vehicle.
  2. Delivers heated or cooled air to maintain the vehicle interior temperature and comfort level.
  3. Cooling or heating can be adjusted to maintain the desired temperature.
  4. Uses a reheat method to provide conditioned air to the passenger compartment.
  5. All airflow from the blower motor passes through the A/C evaporator core.
  6. Temperature blending is controlled by the temperature blend door(s), which regulate(s) the amount of air that flows through and around the heater core, where it is then mixed and distributed.

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 heater core.

The heater core is located in the heater core and evaporator core housing.

Blower Motor

The blower motor pulls air from the air inlet and forces it into the heater core and evaporator core housing where it is mixed and distributed.

The blower motor is located on the bottom of the heater core and evaporator core housing below the glove compartment.

Heater Core and Evaporator Core Housing

The heater core and evaporator core housing directs airflow from the blower motor through the evaporator core and heater core. All airflow from the blower motor passes through the evaporator core. The airflow is then directed through or around the heater core by the temperature blend door(s). Vehicles equipped with dual-zone electronic automatic temperature control (EATC) use a partitioned heater core and evaporator core housing with 2 electric actuator-positioned temperature blend doors. This allows for separate temperatures to be selected for the driver and passenger sides of the passenger compartment. Manual systems use a single electric actuator-positioned temperature blend door to direct airflow through or around the heater core.

The heater core and evaporator core housing is mounted to the passenger compartment side of the dash panel.

Auxiliary Coolant Flow Pump (Hybrid Only)

An auxiliary coolant flow pump is used only on hybrid vehicles to improve engine coolant circulation at low engine speeds or when the engine is OFF.

The auxiliary coolant flow pump will be disabled when any of the following conditions are present

  1. The climate control module is set to the OFF position.
  2. The ambient temperature is above 32°C (90°F).
  3. The coolant temperature is less than -10°C (14°F).
  4. The engine speed is above 4000 RPM.

When none of the listed conditions are present, the auxiliary coolant flow pump is controlled by a strategy included in the PCM software. The control strategy monitors the ambient temperature, coolant temperature and engine RPM. As the ambient temperature and/or coolant temperature increase, the auxiliary coolant flow pump will shut down at lower engine speeds. For example, when both the ambient temperature is above 16°C (60°F) and the engine coolant temperature is above 66°C (150°F), the control strategy will shut off the auxiliary coolant flow pump at 2000 RPM. When both the ambient temperature is above 24°C (75°F) and the engine coolant temperature is above 66°C (150°F), the control strategy will shut off the auxiliary coolant flow pump regardless of engine speed.

To verify auxiliary coolant flow pump operation, allow the vehicle to cool in a cool location. Start the engine and let the engine idle until it shuts down automatically. Select the FLOOR mode on the HVAC module at the highest temperature setting and HI blower speed. If the auxiliary coolant flow pump is inoperative or is not producing adequate coolant flow, the passenger compartment air discharge temperature will quickly decrease and further diagnosis is required. Refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS - HYBRID article. If the auxiliary coolant flow pump is operating normally, the passenger compartment air discharge temperature will remain steady, or slowly decrease.

The auxiliary coolant flow pump is mounted on the lower LH side of the cooling fan shroud.

Air Conditioning (A/C) Compressor - 2.3L

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 163

Scheme 163
ItemPart NumberDescription
1A/C clutch field coil electrical connector (part of 19B573)
2W713281A/C compressor bolt (3 required)
3W520413A/C compressor fitting nut (suction and discharge) (2 required)
419703A/C compressor
519B596O-ring seal and gasket seal kit
619B596O-ring seal and gasket seal kit

Air Conditioning (A/C) Compressor - 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 164

Scheme 164
ItemPart NumberDescription
1W520413A/C compressor fitting nut (suction and discharge) (2 required)
2A/C clutch field coil electrical connector (part of 19B573)
3W713281A/C compressor bolt (3 required)
419703A/C compressor
519B596O-ring seal and gasket seal kit
619B596O-ring seal and gasket seal kit

Air Conditioning (A/C) Compressor - Hybrid

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 165

Scheme 165
ItemPart NumberDescription
1W704692A/C compressor manifold bolt
2A/C clutch field coil electrical connector (part of 12B637)
3W711824A/C compressor bolt (4 required)
419703A/C compressor
519E889O-ring seal (2 required)
CAUTIONIf installing a new A/C compressor due to an internal failure of the old unit, carry out the following procedures to remove contamination from the A/C system. Failure to remove contamination from the A/C system, if present, will result in poor A/C performance and/or damage to the new A/C compressor and other components. If A/C flushing equipment is available, carry out flushing of the A/C system prior to installing a new A/C compressor. For additional information, refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS article. If A/C flushing equipment is not available, carry out filtering of the A/C system after a new A/C compressor has been installed. For additional information, refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS article. Install a new thermostatic expansion valve (TXV), as directed by the A/C flushing or filtering procedure. Install a new auxiliary TXV, as directed by the A/C flushing or filtering procedure. Install a new passenger zone valve. For additional information, refer to Passenger Zone Valve . Install a new battery zone valve. For additional information, refer to AUXILIARY CLIMATE CONTROL - HYBRID article. Install a new receiver/drier as directed by the A/C flushing or filtering procedure.

Note. Installation of a new receiver/drier is not required when repairing the A/C system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the receiver/drier.

Note. If installing a new A/C compressor, the A/C clutch disc and hub, A/C compressor pulley and A/C clutch field coil must be inspected and transferred from the old unit to the new unit if suitable for reuse.

  1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING AND LIFTING»(ref-292146) article.
  2. Recover the refrigerant. For additional information, refer to «CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS»(ref-292158) article.
  3. Remove the RH lower engine splash shield.
  4. Release the tensioner and remove the drive belt from the A/C compressor pulley.
  5. Remove the A/C compressor manifold bolt and disconnect the manifold and tube assembly from the A/C compressor. Discard the O-ring seals. To install, tighten to 20 Nm (15 lb-ft).
  6. Disconnect the A/C clutch field coil electrical connector.
  7. Remove the 4 A/C compressor bolts and the A/C compressor. To install, tighten to 25 Nm (18 lb-ft).
  8. To install, reverse the removal procedure. If a new A/C compressor is to be installed, the clutch assembly must be transferred from the old unit to the new unit. For additional information, refer to «Clutch and Clutch Field Coil - Hybrid»(ref-292181-S37890578392008073100000) . Install new O-ring seals. If not filtering the A/C system, lubricate the refrigerant system with the correct amount of clean PAG oil. For additional information, refer to «CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS»(ref-292158) article.
  9. Evacuate, leak test and charge the refrigerant system. For additional information, refer to «CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS»(ref-292158) article.

Scheme 166

Scheme 166: Air Conditioning (A/C) Evaporator Discharge Air Temperature Sensor
ItemPart NumberDescription
1Instrument panel wire harness pin-type retainer (part of 14401)
2A/C evaporator discharge air temperature sensor electrical connector (part of 19D887)
319C734A/C evaporator discharge air temperature sensor

Air Conditioning (A/C) Pressure Relief Valve - 2.3L, 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 167

Scheme 167
ItemPart NumberDescription
119D644A/C pressure relief valve
2O-ring seal (part of 19D644)

Clutch and Clutch Field Coil - 2.3L, 3.0L (4V)

Special Tools Illustration Tool Name Tool Number Protector, A/C Compressor Shaft 412-137 Installer, A/C Clutch 412-136

Scheme 168

Scheme 168: Clutch and Clutch Field Coil - 2.3L, 3.0L (4V)
ItemPart NumberDescription
1A/C clutch disc and hub bolt (part of 19D784)
2A/C clutch disc and hub (part of 19D784)
3A/C clutch hub disc and hub spacer (part of 19D784)
4A/C compressor pulley snap ring (part of 19D784)
5A/C compressor pulley (part of 19D784)
6A/C clutch field coil screws (4 required) (part of 19D784)
7A/C clutch field coil (part of 19D784)

Clutch and Clutch Field Coil - Hybrid

Special Tools Illustration Tool Name Tool Number Remover, Compressor Pulley 412-001 (T71P-19703-B) Compressor Clutch Holding Tool 412-098 (T94P-19703-AH) Installer, A/C Compressor Pulley 412-109 (T97P-19D786-A)

Scheme 169

Scheme 169: Clutch and Clutch Field Coil - Hybrid

Scheme 170

Scheme 170
ItemSpecification
Silicone Gasket and Sealant TA-30WSE-M4G323-A4

Material

Scheme 171

Scheme 171
ItemPart NumberDescription
1W710491A/C clutch disc and hub nut
219D786A/C clutch disc and hub
319D648A/C clutch disc and hub spacer
4W701742A/C compressor pulley snap ring
519D784A/C compressor pulley
6W704579A/C clutch field coil snap ring
7W500200Thermal protection switch bolt
819E790Thermal protection switch bracket
919D798A/C clutch field coil and thermal protection switch assembly

Compressor to Condenser Discharge Line - 2.3L

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 172

Scheme 172
ItemPart NumberDescription
1W520413Condenser inlet fitting nut
2W520413A/C compressor discharge fitting nut
319972Compressor-to-condenser discharge line
419B596O-ring and gasket seal kit (2 required)

Compressor to Condenser Discharge Line - 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 173

Scheme 173
ItemPart NumberDescription
1W520413Condenser inlet fitting nut
2W520413A/C compressor discharge fitting nut
319972Compressor-to-condenser discharge line
419B596O-ring and gasket seal kit (2 required)

Condenser Core - 2.3L, 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 174

Scheme 174
ItemPart NumberDescription
1W707399Radiator bracket bolt (4 required)
28B068RH radiator bracket
38B445LH radiator bracket
4N606676Condenser bolt (2 required)
5W520413Condenser fitting nut (outlet and inlet) (2 required)
6Transmission cooler lines
719712Condenser core
819B596O-ring seal and gasket seal kit (2 required)

Condenser Core - Hybrid

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 175

Scheme 175
ItemPart NumberDescription
1W707399Radiator bracket bolt (4 required)
28B068RH radiator bracket
38B445LH radiator bracket
4N606676Condenser bolt (2 required)
5W520413Condenser fitting nut (outlet and inlet) (2 required)
619E889O-ring seal (2 required)
719712Condenser core

Condenser to Receiver Drier Line

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 176

Scheme 176
ItemPart NumberDescription
1W707137Compressor manifold and tube bracket nut
2W520413Condenser outlet fitting nut
3W520413Evaporator outlet line fitting nut
4W520413Auxiliary evaporator outlet line fitting nut
5W520413Receiver/drier inlet fitting nut
619835Condenser-to-receiver/drier line
719B596O-ring seal and gasket seal kit (2 required)
819E889O-ring seal (3 required)
919B596O-ring seal and gasket seal kit

Evaporator Inlet Line - 2.3L, 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 177

Scheme 177
ItemPart NumberDescription
1W520413Receiver/drier outlet fitting nut
2W711470Evaporator inlet line bracket nut
3W520413Thermostatic expansion valve (TXV) fitting nut
419835Evaporator inlet line
519B596O-ring and gasket seal kit
619B596TXV fitting gasket seal kit (2 pieces from kit required)

Evaporator Inlet Line - Hybrid

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 178

Scheme 178
ItemPart NumberDescription
1W520413Evaporator outlet line fitting nut
2W520413Auxiliary evaporator outlet line fitting nut
3Low-charge protection switch electrical connector (part of 14290)
4W520413Thermostatic expansion valve (TXV) fitting nut
5W707137Passenger zone valve bracket nut
6W520413Auxiliary evaporator inlet line fitting nut
7W520413Receiver/drier outlet fitting nut
8Passenger zone valve electrical connector (part of 14290)
9A/C line bracket (part of 19835)
1019835Evaporator inlet line
1119B596O-ring seal and gasket seal kit (2 required)
1219B596O-ring seal and gasket seal kit
1319E889O-ring seal
1419B596TXV fitting gasket seal kit (2 pieces from kit required)

Evaporator Outlet Line - 2.3L, 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 179

Scheme 179
ItemPart NumberDescription
1W520413A/C compressor suction fitting nut
2Wire harness clip (part of 12B637)
3Low-charge protection switch electrical connector (part of 14290)
4W520413Thermostatic expansion valve (TXV) fitting nut
5Coolant hose clip (part of 8C633)
619867Evaporator outlet line
719B596O-ring seal and gasket seal kit
819B596TXV fitting gasket seal kit (2 pieces from kit required)

Evaporator Outlet Line - Hybrid

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 180

Scheme 180
ItemPart NumberDescription
1W520413Evaporator outlet line fitting nut
2Low-charge protection switch electrical connector (part of 14290)
3W520413Thermostatic expansion valve (TXV) fitting nut
419835Evaporator outlet line
519B596TXV fitting gasket seal kit (2 pieces from kit required)
619B596O-ring seal and gasket seal kit
ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 181

Scheme 181
ItemPart NumberDescription
1W520413Thermostatic expansion valve (TXV) fitting nut
218472Heater core inlet hose
318472Heater core outlet hose
4W707137Heater core and evaporator core housing nut (6 required)
519B555Heater core and evaporator core housing
619B596TXV fitting gasket seal kit (2 pieces from kit required)

Passenger Zone Valve

ItemSpecification
PAG Refrigerant Compressor Oil (R134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 182

Scheme 182
ItemPart NumberDescription
1Passenger zone valve electrical connector (part of 14290)
2Passenger zone valve fitting (2 required) (part of 19835)
3W707137Passenger zone valve nut
419E653Passenger zone valve

Receiver Drier - 2.3L, 3.0L (4V)

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 183

Scheme 183
ItemPart NumberDescription
1W520413Condenser outlet fitting nut
2Dual-function pressure switch electrical connector (part of 14290)
3W520413Receiver/drier outlet fitting nut
419867Evaporator outlet line
5W707137Receiver/drier nut (2 required)
619C836Receiver/drier
719B596O-ring seal and gasket seal kit (2 required)

Receiver Drier - Hybrid

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 184

Scheme 184
ItemPart NumberDescription
1W520413Evaporator outlet line fitting nut
2W520413Auxiliary evaporator outlet line fitting nut
3W707137Passenger zone valve bracket nut
4Dual-function pressure switch electrical connector (part of 14290)
5W520413Auxiliary evaporator inlet line fitting nut
6W520413Receiver/drier inlet fitting nut
7W520413Receiver/drier outlet fitting nut
8W707137Receiver/drier nut (2 required)
919959Receiver/drier
1019B596O-ring seal and gasket seal kit
1119B596O-ring seal and gasket seal kit (2 required)
1219E889O-ring seal

Thermostatic Expansion Valve

ItemSpecification
PAG Refrigerant Compressor Oil (R-134a Systems) YN-12-DWSH-M1C231-B

Material

Scheme 185

Scheme 185
ItemPart NumberDescription
1W520413Thermostatic expansion valve (TXV) fitting nut
219B596TXV fitting gasket seal kit (2 pieces required from kit)
3TXV bolt (2 required) (part of 19849)
419849TXV
519E889O-ring seal
619E889O-ring seal
7TXV fitting stud (part of 19849)