Lincoln Aviator: Second Row Climate Control / Description and Operation - Second Row Climate Control - System Operation and Component Description

System Operation

System Diagram

Network Message Charts

  Module Network Input Messages - APIM

  Module Network Input Messages - FCIMB

  Module Network Input Messages - HVAC Control Module

Second Row Climate Control

For diagnosis and testing of the second row climate control system,
Refer to: Climate Control System (412-00 Climate Control System - General Information, Diagnosis and Testing).

The second row climate control system operation is determined by the settings on the FCIMB control panel selection, FDIM or from the center console control panel selection. The second row climate control components are hard wired to the HVAC control module. Air is cooled and dehumidified by the front evaporator core, which requires A/C compressor operation.

For second row climate control access information through FCIMB control panel selection or FDIM Sync™ 3, refer to Owner's Literature.

Second Row Climate Controls - FCIMB

The customer interface from the front (main) FCIMB panel for the second row climate system consists of the following selections:

• Second row passenger temperature control
• Second row climate control lock
• Second row passenger power
• Second row fan speed control

For illustrations and rear climate control button operation information, refer to the Owner's Literature.

Second Row Controls - FDIM

The customer interface from the touchscreen has access to the rear climate control system. In the lower right of the main touchscreen, touch Climate. On the climate screen, touch Rear from the lower right corner. Rear climate control settings appear at the bottom of the screen:

• Touch the power icon to turn the rear climate control functions off and on.
• Touch Rear Control to allow the rear seat passengers to adjust the rear climate settings. Touch it again to prevent the rear seat passengers from adjusting the settings. Rear Control automatically turns off when you use the touchscreen to adjust the rear climate settings.
• Touch + or – to adjust the temperature.
• To adjust fan speed, touch + or – next to the fan icon.
• Touch Rear again to close the rear controls. Closing the rear climate control functions does not affect their current settings.

For illustrations and second climate control button operation information, refer to the Owner's Literature.

Second Row Controls - Center Console

The customer interface from the rear non touch screen RHVAC control panel or rear touch screen RACM control panel for the second row climate control system consist of the following selections.

• Second row passenger temperature control
• Second row climate control lock
• Second row passenger power
• Second row fan speed control
• Second row linked with rear (third row) climate control (rear touch screen only)

For illustrations and second climate control button operation information, refer to the Owner's Literature.

Control System Logic

The second row climate control can be controlled by either the main front HVAC controls or the center console controls. When a selection is made on the rear climate control panel, known as the rear non touch screen RHVAC control module or rear touch screen RACM, a message is sent to the HVAC control module over the CAN. The non touch screen RHVAC control module communicates on the MS-CAN. The rear touch screen RACM communicates on the HS-CAN3.

Vehicles equipped with a rear non touch screen RHVAC control module, the second row and rear (third row) climate controls are controlled as one climate zone. When the climate control settings are selected to heat or cool, both rows are changed as one climate zone.

Vehicles equipped with a rear touch screen RACM, the second row and rear (third row) climate controls are independently controlled as two separate climate zones. When the climate control settings are selected the two zones are heated or cooled as a climate control zone for the second row and a climate control zone for the rear (third row). Through a setting in the rear touch screen RACM, the two zones can also be linked together.

Air Handling

The second row climate control system has the following features:

• The driver has primary control of the second row climate control system or can transfer control to the second row passenger control panel.
• The second row air distribution door actuator controls the air flow from the front climate control housing based on the control selection. The second row air flow shut off door actuator cuts off the air flow from the main climate control housing.
• The second row blower motor moves and recirculates the air from the main climate control housing.
• The second row temperature door and the second row rear air distribution door are controlled by electric actuator motors.
• The airflow is directed to the passengers through the second row adjustable registers. The heater floor duct supplies air to a fixed register, which is integral to the side trim panel.

The HVAC control module sends a PWM signal to the second row blower motor control module to control the second row blower speed. The second row blower motor control module provides variable ground feed for the blower motor. A delay function provides a gradual increase or decrease in blower motor speed under all conditions.

Component Description

Component Description

Rear Climate

RACM

The rear touchscreen is used to adjust the rear (second and third row) climate control and other functions. It communicates these inputs over the HS-CAN3. For more information on the RACM,
Refer to: Information and Entertainment System - System Operation and Component Description (415-00 Information and Entertainment System - General Information, Description and Operation).

RHVAC Control Module

The rear non touch screen RHVAC control module is used by the rear vehicle occupants to request changes to the rear climate control system. The requests are sent to the HVAC control module over the MS-CAN.

Rear temperature sensor - vehicles with: second row seats

The rear temperature sensor - vehicles with: second row seats is located in the headliner above the second row seating in the microphone bezel assembly. The rear temperature sensor contains a thermistor which separately measures the in-vehicle air temperature, then sends those readings to the HVAC control module. The HVAC control module may adjust the rear climate control system based on the second row seat rear temperature sensor information to maintain the desired temperature of the rear passenger cabin air.

Rear temperature sensor - vehicles with: third row seats

The rear temperature sensor - vehicles with: third row seats is located in the headliner above the third row seating in the microphone bezel assembly. The rear temperature sensor contains a thermistor which separately measures the in-vehicle air temperature, then sends those readings to the HVAC control module. The HVAC control module may adjust the rear climate control system based on the third row seat rear temperature sensor information to maintain the desired temperature of the rear passenger cabin air.

Second Row Air Discharge Temperature Sensor

The second row air discharge temperature sensors, located in the center console, contain a thermistor and is an input to the HVAC control module. The sensor varies its resistance with the temperature. As the temperature rises, the resistance falls. As the temperature falls, the resistance rises. The HVAC control module uses the sensor information to maintain the desired temperature of the passenger cabin air.

Second Row Air Distribution Door Actuator

The second row air distribution door actuator is located in the center console. The second row air distribution door actuator moves the door on command from the HVAC control module based on input from either the front or rear climate controls.

The second row air distribution door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC control module to monitor the position of the second row air distribution door. 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 circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal to the HVAC control module from the contact wiper indicates the position of the second row air distribution door.

Second Row Air Flow Shut Off Door Actuator

The second row air flow shut off door actuator is located in the center console at the base of the climate control housing. The second row air flow shut off door actuator moves the shut off door on command from the HVAC control module.

The second row shut off door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC control module to monitor the position of the second row shut off door closing off the air flow from the front climate control housing. 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 circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal to the HVAC control module from the contact wiper indicates the position of the second row shut off door.

Second Row Blower Motor Control Module

The second row blower motor control module is located in the center console. The second row blower motor control module and the blower motor are combined into one assembly called the second row blower motor control module. The second row blower motor pulls air from the front HVAC control module and forces it into the second row climate control housing and the plenum where it is distributed. The second row blower motor speed control uses a PWM signal from the HVAC to determine the desired blower speed and varies the ground feed for the second row blower motor.

Second Row Temperature Door Actuator

The second row temperature door actuator is located in the front climate control housing. The second row temperature door actuator moves the temperature door on command from the HVAC control module based on input from either the front or rear climate controls.

The second row temperature door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC control module to monitor the position of the second row temperature door. 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 circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal to the HVAC control module from the contact wiper indicates the position of the rear temperature door.