Heating and Ventilation Land Rover Range Rover L322

SPECIFICATION

TORQUE SPECIFICATIONS

Scheme 77

OVERVIEW

The heating and ventilation system controls the temperature and flow of air supplied to the vehicle interior. The system consists of

1. An air inlet duct.
2. A heater.
3. A rear blower.
4. Two ventilation outlets.

Fresh or recirculated air flows into the heater from the inlet duct. The blower, and ram effect when the vehicle is moving, forces the air through the heater. Air from the cabin exhausts through the ventilation outlets.

Some vehicles may be fitted with a 4 zone climate control system. Refer to Auxiliary Climate Control .

Scheme 78

The air inlet duct directs fresh air from above the hood into the heater. The air inlet duct is centrally mounted on the engine bulkhead, below a ventilation grill in the hood, and secured to the bulkhead closing panels.

The cabin air filter is installed in the air inlet duct behind a hinged door. Refer to Air Distribution and Filtering .

HEATER

The heater controls the temperature, volume and distribution of air supplied to the distribution ducts as directed by selections made on the automatic temperature control (ATC) module control panel. The heater is installed on the vehicle center-line, between the instrument panel and the engine bulkhead. The heater consists of a casing formed from a series of plastic moldings. Internal passages integrated into the casing guide the air through the casing and separate it into two flows, one for the left-hand (LH) outlets and one for the right-hand (RH) outlets. Two drain outlets at the bottom of the casing are connected to overboard drain hoses in the sides of the transmission tunnel.

The heater incorporates

1. A blower.
2. A blower motor control module.
3. A heater core.
4. Control doors.
5. Control door motors.
6. The thermostatic expansion valve and the evaporator of the air conditioning (A/C) system. Refer to «Air Conditioning»(/land-rover/range-rover/l322-2005-2009/remont/automatic-hvac-system/#air-conditioning) .
7. The evaporator temperature sensor and 2 heater temperature sensors. Refer to «Control Components»(/land-rover/range-rover/l322-2005-2009/remont/ac-compressor/#control-components) .

Scheme 79

BLOWER

The blower is installed between the air inlets and the evaporator, and consists of 2 open hub, centrifugal fans powered by a single electric motor. Operation of the electric motor is controlled by the automatic temperature control (ATC) module via the blower motor control module (voltage amplifier) installed in the outlet of the right-hand (RH) fan.

To produce the seven blower speeds the automatic temperature control (ATC) module outputs a stepped control voltage between 0 and 8 V to the blower motor control module, which regulates a battery power feed from the central junction box (CJB) to the blower. The control voltage changes, in 1 V steps, between 2 V (blower speed 1) and 8 V (blower speed 7). If the control voltage is less than 2 V the blower is off.

Scheme 80

HEATER CORE

The heater core is internally divided into two separate halves, with separate coolant inlets for each half and a common coolant outlet. On the manual system, the two coolant inlets are connected to a common feed from the single coolant valve. Each coolant inlet pipe is connected to a feed from a separate coolant valve.

CONTROL DOORS

Control doors in the heater control the source of inlet air and the distribution and temperature of outlet air.

On both the manual and automatic heaters, a fresh/recirculated air door is installed in the air inlet on each side of the heater. A stepper motor drives the left-hand (LH) fresh/recirculated air door and a Bowden cable transmits the drive from the left-hand (LH) to the right-hand (RH) fresh/recirculated air door. On the automatic system, a ram air door is installed inside each fresh/recirculated air door. A stepper motor drives the right-hand (RH) ram air door and a Bowden cable transmits the drive from the right-hand (RH) to the left-hand (LH) ram air door.

Each side of the heater contains separate distribution doors for the footwell, face level and windshield. The related doors on each side of the heater are installed on common drive spindles. On the manual heater, the distribution doors are driven by Bowden cables connected to a cam mechanism, which, in turn, is driven by a stepper motor. On the automatic heater, each set of distribution doors is driven by a separate stepper motor.

On both the manual and automatic heaters, a blend door is installed below the face level registers. The blend door is driven by a Bowden cable connected to a thumbwheel on the center face level registers in the instrument panel, and allows the temperature of face level air to be modified with cold air direct from the evaporator.

Scheme 81

The heater incorporates an additional blend door for the air directed to the rear passenger face level register. This allows the temperature of rear face level air to be adjusted independently from the temperatures selected on the control panel of the automatic temperature control (ATC) module. The blend door is driven by a stepper motor controlled by a thumbwheel on the rear passenger face level register. The blend door is also used to close off the rear passenger face level register when maximum air output is required for the front outlets, e.g. when defrost is selected.

CONTROL DOOR MOTORS

Two types of electrical stepper motor are used to operate the control doors in the heater. A conventional 500 Hz stepper motor operates the recirculation doors. Five bus controlled 200 Hz stepper motors operate the ram air, distribution (windshield, face level and footwell) and the rear face level temperature control doors. All of the stepper motors are controlled by the automatic temperature control (ATC) module. None of the stepper motors are interchangeable.

Scheme 82

Each bus controlled stepper motor incorporates a microprocessor and is connected to an M bus from the automatic temperature control (ATC) module, which consists of three wires making up power, ground and signal circuits. The microprocessor in each bus controlled stepper motor is programmed with a different address. Each M bus message from the automatic temperature control (ATC) module contains the address of an individual bus controlled stepper motor, so only that motor responds to the message.

None of the stepper motors incorporate a feedback potentiometer. Instead, the automatic temperature control (ATC) module determines the positions of the doors by using either their closed or open position as a datum and memorizing the steps that it drives the individual stepper motors. Each time the ignition is switched on, the automatic temperature control (ATC) module checks the memorized position of the stepper motors against fixed values for the current system configuration. If there is an error (e.g. after a power supply failure during operation or after replacement of the automatic temperature control (ATC) module), the automatic temperature control (ATC) module calibrates the applicable stepper motors, to re-establish the datums, by driving them fully closed or open before re-setting them to their nominal position. A calibration run can also be invoked using the Land Rover approved diagnostic system.

When any of the control doors are set to fully closed or open, the automatic temperature control (ATC) module signals the related stepper motor to move the appropriate number of steps in the applicable direction. To accommodate build tolerances and wear, and to ensure the doors are held in the selected position, every 20 seconds the automatic temperature control (ATC) module signals the stepper motor to move an additional 10 steps in the relevant direction.

REAR BLOWER

The blower is installed between the front seats, in the rear face air duct, and consists of an open hub, centrifugal fan powered by an electric motor. Operation of the electric motor is controlled by a rotary control on the rear passenger face vent via the automatic temperature control (ATC) module and a blower motor control module (voltage amplifier) installed in the outlet of the fan.

The rotary control allows 7 differing blower speeds to be selected. The position of the rotary control is monitored by the automatic temperature control (ATC) module, which then outputs a proportional control voltage between 0 and 5 V to the blower motor control module. The blower motor control module regulates a battery power feed from the rear blower relay to the blower to produce the related blower speed.

The rear blower relay is installed in the AJB (auxiliary junction box) and energized while the ignition is on.

Some vehicles may be fitted with a 4 zone climate control system. Refer to Auxiliary Climate Control .

Scheme 83

VENTILATION OUTLETS

The ventilation outlets promote the free flow of air through the passenger compartment. The outlets are installed in the left-hand (LH) and right-hand (RH) rear quarter body panels and vent passenger compartment air into the sheltered area between the rear quarter body panels and the rear bumper.

REMOVAL

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Scheme 86

1. Make the air bag supplemental restraint system (SRS) safe. Refer to «Standard Workshop Practices»(/land-rover/range-rover/l322-2005-2009/remont/oem-general-information/#general-information) .
2. Disconnect the battery ground cable. Refer to «Specifications»(/land-rover/range-rover/l322-2005-2009/remont/charging-system/#charging-system-general-information__specifications) .
3. Remove the heater and evaporator core housing. See «HEATER CORE AND EVAPORATOR CORE HOUSING»(/land-rover/range-rover/l322-2005-2009/remont/automatic-hvac-system/#heating-and-ventilation) .
4. Remove the passive anti-theft system (PATS) module. Release the 2 clips.
5. Remove the blower motor cover. Release the 3 clips.
6. Remove the blower motor. Remove the 3 screws. Disconnect the electrical connector. Release the wiring harness grommet. Reposition the wiring harness.

INSTALLATION

1. Install the blower motor. Secure the wiring harness grommet. Connect the electrical connector. Install the screws.
2. Install the blower motor cover. Install the clips.
3. Install the PATS module. Secure the clips.
4. Install the heater and evaporator core housing. See «HEATER CORE AND EVAPORATOR CORE HOUSING»(/land-rover/range-rover/l322-2005-2009/remont/automatic-hvac-system/#heating-and-ventilation) .
5. Connect the battery ground cable. Refer to «Specifications»(/land-rover/range-rover/l322-2005-2009/remont/charging-system/#charging-system-general-information__specifications) .

HEATER CONTROL VALVE

No data available.

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1. Set the footwell duct air outlet to closed.
2. Make the air bag supplemental restraint system (SRS) safe. Refer to «Standard Workshop Practices»(/land-rover/range-rover/l322-2005-2009/remont/oem-general-information/#general-information) .
3. Disconnect the battery ground cable. Refer to «Specifications»(/land-rover/range-rover/l322-2005-2009/remont/charging-system/#charging-system-general-information__specifications) .
4. Remove the heater and evaporator core housing. See «HEATER CORE AND EVAPORATOR CORE HOUSING»(/land-rover/range-rover/l322-2005-2009/remont/automatic-hvac-system/#heating-and-ventilation) .
5. Reposition the heater and evaporator core housing for access.
6. Remove the left-hand footwell duct. Remove the 2 screws.
7. Remove the left-hand air intake duct. Remove the 4 screws.
8. Remove the gasket from the heater core inlet and outlet pipes.
9. Remove the heater core, inlet and outlet pipes. Remove the 2 screws. Remove and discard the 3 O-ring seals.
10. Remove the thermostatic expansion valve cover. Release the wiring harness from the 2 tangs. Remove the 4 screws.
11. Remove the right-hand footwell duct. Remove the 4 screws. Remove the clip.
12. Disconnect the floor duct actuator motor electrical connector.
13. Release the evaporator temperature sensor from the heater and evaporator core housing.
14. Remove the heater and evaporator core housing lower cover. Remove the 7 screws. Remove the 4 clips.
15. Remove the heater core.

1. Install the heater core.
2. Install the heater and evaporator core housing lower cover. Install the screws. Install the clips.
3. Install the evaporator temperature sensor to the heater and evaporator core housing.
4. Connect the floor duct actuator motor electrical connector.
5. Install the right-hand footwell duct. Install the screws. Install the clip.
6. Install the thermostatic expansion valve cover. Install the screws. Secure the wiring harness to the tangs.
7. Install the heater core, inlet and outlet pipes. Clean the component mating faces. Lubricate and install the new O-rings. Tighten the screws to 10 Nm (7 lb.ft).
8. Install the gasket to the heater core inlet and outlet pipes.
9. Install the left-hand air intake duct. Install the screws.
10. Install the left-hand footwell duct. Install the screws.
11. Reposition the heater and evaporator core housing for access.
12. Install the heater and evaporator core housing. See «HEATER CORE AND EVAPORATOR CORE HOUSING»(/land-rover/range-rover/l322-2005-2009/remont/automatic-hvac-system/#heating-and-ventilation) .
13. Connect the battery ground cable. Refer to «Specifications»(/land-rover/range-rover/l322-2005-2009/remont/charging-system/#charging-system-general-information__specifications) .

1. Remove the in-vehicle crossbeam. Refer to «In-Vehicle Crossbeam»(/land-rover/range-rover/l322-2005-2009/remont/gauges-instrument-panels/#instrument-panel-and-console) .
2. With assistance, remove the heater and evaporator core housing.

1. With assistance, install the heater and evaporator core housing.
2. Install the in-vehicle crossbeam. Refer to «In-Vehicle Crossbeam»(/land-rover/range-rover/l322-2005-2009/remont/gauges-instrument-panels/#instrument-panel-and-console) .

See also:
• Auxiliary Climate Control
• Air Distribution and Filtering
• Air Conditioning
• Control Components
• Standard Workshop Practices
• Specifications
• In-Vehicle Crossbeam
• HEATER CORE AND EVAPORATOR CORE HOUSING