Heating & Air Conditioning - Service Information: Overview Dodge Journey I

DESCRIPTION

A manual temperature control (MTC) single zone heating-A/C system, automatic temperature controlled (ATC) dual zone heating-A/C system, MTC tri-zone heating-A/C system and an ATC tri-zone heating-A/C system is available on this vehicle.

To maintain the performance level of the heating, ventilation and air conditioning (HVAC) system, the engine cooling system must be properly maintained. The use of a bug screen is not recommended. Any obstructions in front of the radiator or A/C condenser will reduce the performance of the A/C and engine cooling systems.

The engine cooling system includes the radiator, thermostat, radiator hoses and the engine coolant pump. Refer to COOLING for more information before opening or attempting any service to the engine cooling system.

Scheme 6

Note. Single zone HVAC shown. Dual zone similar.

All vehicles are equipped with a common front heater, ventilation and air conditioning (HVAC) housing (1). The heating-A/C system combines A/C, heating, and ventilating capabilities in a single HVAC housing mounted within the passenger compartment beneath the instrument panel. The HVAC housing includes

1. A/C evaporator (2)
2. Mode-air doors (3)
3. Mode door actuator (4)
4. Recirculation-air door and actuator (5)
5. Particulate air filter (when equipped) (6)
6. Blower motor (7)
7. Blower motor resistor or power module (depending on system application) (8)
8. Blend door actuator(s) (9)
9. Heater core (10)
10. Evaporator temperature sensor (11)
11. Blend-air door(s) (12)

Note. An electric positive temperature coefficient (PTC) heater is used on vehicles when equipped with the 2.0L diesel engine. The PTC heater unit compensates for the lower engine coolant temperatures produced by the diesel engine. The PTC heater unit is mounted in the HVAC air distribution housing, downstream of the heater core. See Heating and Air Conditioning/Cabin Heater/UNIT, Heater - Description .

Based upon the system mode selected, conditioned air can exit the front HVAC housing through one or a combination of the three main housing outlets: defrost, panel or floor. The defrost and panel outlets are located on the top of the HVAC air distribution housing and the floor outlets are located on each side of the distribution housing. Once the conditioned air exits the HVAC housing, it is further directed through molded plastic ducts to the various outlets within the vehicle interior. These outlets and their locations are as follows

1. Defroster Outlet - Two defroster outlets are located in the center of the instrument panel, near the base of the windshield.
2. Side Window Demister Outlets - There are two side window demister outlets, one is located at each outboard end of the instrument panel, near the A-pillars.
3. Panel Outlets - There are four panel outlets in the instrument panel, one located near each outboard end of the instrument panel facing the rear of the vehicle and two located near the top of the instrument panel center bezel.
4. Front Floor Outlets - There are two front floor outlets, one located on each side the floor panel center tunnel behind the instrument panel.
5. Rear Seat Floor Outlets - There are two rear seat floor outlets, one located on each side of the floor panel near the front of each rear seat foot well.

Scheme 7

The tr-zone heating-A/C systems are equipped with a rear heater-A/C housing (1) that combines A/C and heating capabilities into a single unit mounted within the passenger compartment behind the right quarter interior trim panel. The rear heater-A/C housing includes

1. Mode door and actuator (2)
2. Blend door and actuator (3)
3. Blower motor (4)
4. Blower motor resistor or power module (5) (depending on control system)
5. A/C evaporator (6)
6. A/C expansion valve (7)
7. Wire harness (8)
8. Heater core (9)

Based upon the rear temperature selected, conditioned air can exit the rear heater-A/C housing through one or a combination of the two rear housing outlets: ceiling or floor. The ceiling outlet is located at the top rear of the housing and the floor outlet is located at the top front of the rear housing. Once the conditioned air exits the rear heater-A/C housing, it is further directed through molded plastic ducts to the outlets at the rear of the passenger compartment. These outlets and their locations are as follows

1. Ceiling Outlets - There are four ceiling outlets in the headliner. One located at each outboard side of the intermediate seat position and one located in front of each rear seat position.
2. Floor Outlet - There is one floor outlet in the right quarter interior trim panel located behind the right rear door area.

OPERATION

The standard front and available rear heating-A/C systems used in this vehicle are blend-air type systems. In a blend-air system, a blend-air door controls the amount of conditioned air that is allowed to flow through, or around the heater core. In the available front dual zone system, separate blend-air doors are used to provide completely independent side-to-side temperature control of the discharge air. The temperature control(s) determines the discharge air temperature(s) by operating the blend door actuator(s), which move the blend-air door(s). This design allows almost immediate control of output air temperature(s).

Scheme 8

Note. Typical blend-air type HVAC system shown.

The heating-A/C system pulls outside (ambient) air through the fresh air intake (4) located at the cowl panel at the base of the windshield and into the air inlet housing above the heating, ventilation and air conditioning (HVAC) housing and passes through the A/C evaporator (7). Air flow is then directed either through or around the heater core (2). This is done by adjusting the position of the blend-air door(s) (3) with the temperature control(s) located on the A/C-heater control in the instrument panel. Air flow is then directed out the floor outlet (8), instrument panel outlet (10) or the defroster outlet (1) in various combinations by adjusting the position of the mode-air doors (9 and 11) using the mode control located on the A/C-heater control. The temperature and mode control use electrical actuators to operated the air doors.

The velocity of the air flow out of the outlets can be adjusted with the blower speed control located on the A/C-heater control.

The fresh air intake can be shut off by pressing the Recirculation button on the A/C-heater control. This will operate the electrically actuated recirculation-air door (5), which closes off the fresh air intake. With the fresh air intake closed, the conditioned air within the vehicle is pulled back into the HVAC housing through the recirculation air intake (6).

The A/C compressor can be engaged by pressing the A/C (snowflake) button on the A/C-heater control. It will automatically engage when the mode control is set in any Mix to Defrost position. This will remove heat and humidity from the air before it is directed through or around the heater core. The mode control on the A/C-heater control is used to direct the conditioned air to the selected system outlets.

The defroster outlets receive airflow from the HVAC housing through the molded plastic defroster duct, which is secured to the top of the instrument panel. The airflow from the defroster outlets is directed by fixed vanes in the defroster outlet grille and cannot be adjusted.

The side window demister outlets receive airflow from the HVAC housing through the defroster duct and molded plastic demister ducts, which are secured to the instrument panel support. The airflow from the side window demister outlets is directed by fixed vanes and cannot be adjusted. The demisters operate when the mode control is set in any Floor to Defrost position.

The instrument panel outlets receive airflow from the HVAC housing through a molded plastic center panel duct and two end panel ducts. The two end panel ducts direct airflow to the left and right instrument panel outlets, while the center panel duct directs airflow to the two center panel outlets. Each of these outlets can be individually adjusted to direct or shut off the flow of air leaving the outlets.

The front and rear floor outlets receive airflow from the HVAC housing through the front and rear floor ducts which are secured to each side of the HVAC housing. The rear seat ducts direct airflow beneath the carpet to the outlets located near the front of each rear seat foot well. None of the floor outlets can be adjusted.

Note. It is important to keep the air intake opening clear of debris. Leaf particles and other debris that is small enough to pass through the cowl opening screen can accumulate within the HVAC housing. The closed, warm, damp and dark environment created within the housing is ideal for the growth of certain molds, mildews and other fungi. Any accumulation of decaying plant matter provides an additional food source for fungal spores, which enter the housing with the fresh intake-air. Excess debris, as well as objectionable odors created by decaying plant matter and growing fungi can be discharged into the passenger compartment during heater-A/C operation if the air intake opening is not kept clear of debris.

The front A/C system is designed for use of non-CFC, R-134a refrigerant and uses an A/C expansion valve (TXV) to meter the flow of refrigerant to the A/C evaporator. To maintain minimum evaporator temperature and prevent evaporator freezing, an evaporator temperature sensor input is supplied to the A/C-heater control. In turn, the powertrain control module (PCM) cycles the A/C compressor clutch off and on as necessary to optimize A/C system performance and to protect the A/C system from evaporator freezing.

The blend door actuators are connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector. The blend door actuator(s) can move the blend-air door(s) in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the blend-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the blend-air door moves in the opposite direction. When the A/C-heater control makes the voltage to both connections high or both connections low, the blend-air door stops and will not move.

The A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the blend door actuator(s) and the blend-air door(s). The A/C-heater control learns the blend-air door stop positions during the calibration procedure and will store a diagnostic trouble code(DTC) for any problems it detects in the blend door actuator circuits.

The blend door actuators are diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The blend door actuators cannot be adjusted or repaired and must be replaced if inoperative or damaged.

The mode door actuator (1) for the heating-A/C system is a reversible, 12-volt Direct Current (DC) servo motor, which is mechanically connected to the mode-air doors. The mode door actuator is located on the right side of the HVAC air distribution housing.

The mode door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2). An output shaft with splines (3) connect it to mode door linkage and integral mounting tabs (4) allow the actuator to be secured to the air distribution housing. The mode door actuator does not require mechanical indexing to the mode-air doors, as it is electronically calibrated by the A/C-heater control.

The A/C-heater control must be recalibrated each time an actuator motor is replaced. Refer to DTC-Based Diagnostics/HVAC - Standard Procedure .

The mode door actuator is interchangeable with the actuators for the recirculation and blend-air doors.

The mode door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the instrument panel wire harness. The mode door actuator can move the mode-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the mode-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the mode-air door moves in the opposite direction. Once the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air door stops and will not move.

The A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the mode door actuator and the mode-air door. The A/C-heater control learns the mode-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the mode door actuator circuits. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The mode door actuator cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

The recirculation door actuator (1) is a reversible, 12 volt direct current (DC) servo motor, which is connected directly to the pivot shaft lever of the recirculation-air door. The recirculation door actuator is located on the right side of the HVAC air inlet housing.

The recirculation door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2), an output shaft with splines (3) connect it to the recirculation door and three integral mounting tabs (4) allow the actuator to be secured to the air inlet housing. The recirculation door actuator does not require mechanical indexing to the recirculation-air door, as it is electronically calibrated by the A/C-heater control.

The A/C-heater control must be recalibrated each time an actuator motor is replaced. Refer to DTC-Based Diagnostics/HVAC - Standard Procedure .

The recirculation door actuator is interchangeable with the actuators for the blend and mode-air doors.

The recirculation door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the instrument panel wire harness. The recirculation door actuator can move the recirculation-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the recirculation-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the recirculation-air door moves in the opposite direction. Once the A/C-heater control makes the voltage to both connections high or both connections low, the recirculation-air door stops and will not move.

The A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the recirculation door actuator and the recirculation-air door. The A/C-heater control learns the recirculation-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the recirculation door actuator circuits. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The recirculation door actuator cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

The blower motor power module is connected to the vehicle electrical system through a dedicated lead and connector of the instrument panel wire harness. A second lead and connector of the instrument panel wire harness is connected to the blower motor. The blower motor power module allows the microprocessor-based automatic temperature control(ATC) A/C-heater control to calculate and provide infinitely variable blower motor speeds based upon either manual blower switch input or the ATC programming using a pulse width modulated (PWM) circuit strategy.

The PWM voltage is applied to a comparator circuit which compares the PWM signal voltage to the blower motor feedback voltage. The resulting output drives the power module circuitry, which provides a linear output voltage to change or maintain the desired blower speed.

The blower motor power module is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The blower motor power module cannot be adjusted or repaired must be replaced if inoperative or damaged.

The blower motor resistor is connected to the vehicle electrical system through a dedicated take out and connector of the instrument panel wire harness. The blower motor resistor has three resistors, each of which will reduce the current flow through the blower motor to change the blower motor speed.

The blower motor control for the heating-A/C system directs the ground path for the blower motor through the correct resistor to obtain the selected speed. With the blower motor control in the lowest speed position, the ground path for the blower motor is applied through all of the resistors. Each higher speed selected with the blower motor control applies the blower motor ground path through fewer of the resistors, increasing the blower motor speed. When the blower motor control is in the highest speed position, the blower motor resistor is bypassed and the blower motor receives a direct path to ground.

The blower motor resistor cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

The ambient air temperature sensor is a variable resistor that operates on a 5-volt reference signal sent by the Totally Integrated Power Module (TIPM). The ambient air temperature sensor is connected to the TIPM through a two-wire lead and connector of the vehicle wire harness. The ambient air temperature sensor changes its internal resistance in response to changes in the outside air temperature, which either increases or decreases the reference signal voltage read by the TIPM. The TIPM converts and broadcasts the sensor data over the Controller Area Network (CAN) IHS bus, where it is read by the ATC A/C-heater control, Powertrain Control Module (PCM) and other vehicle control modules.

The ambient air temperature sensor is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Diagnosis and Testing .

The ambient air temperature sensor cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Scheme 9

The evaporator temperature sensor measures the temperature of the conditioned air downstream of the A/C evaporator. The evaporator temperature sensor is an electrical thermistor (1) mounted on the end of a molded plastic housing (2) that is inserted into the driver side of the HVAC housing near the coldest point of the A/C evaporator. The evaporator temperature sensor is retained in the HVAC housing by two integral retaining tabs (3) and is connected to the vehicle electrical system by use of a wire lead and connector (4) with two terminals.

The evaporator temperature sensor monitors the surface temperature of A/C evaporator and supplies an input signal to the A/C-heater control. The A/C-heater control uses the evaporator temperature sensor input signal to optimize A/C system performance and to protect the A/C system from evaporator freezing. The evaporator temperature sensor will change its internal resistance in response to the temperatures it monitors and is connected to the A/C-heater control through sensor ground circuit and a 5-volt reference signal circuit. As the temperature of the A/C evaporator decreases, the internal resistance of the evaporator temperature sensor decreases.

The A/C-heater control uses the monitored voltage reading as an indication of evaporator temperature. The A/C-heater control is programmed to respond to this input by requesting the powertrain control module (PCM) or the engine control module (ECM) (depending on engine application) to adjust the compressor swash plate angle as necessary to optimize A/C system performance and to protect the A/C system from evaporator freezing. See Heating and Air Conditioning/Plumbing/COMPRESSOR, A/C - Operation .

The evaporator temperature sensor is diagnosed using a scan tool.

The evaporator temperature sensor cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

The infrared sensor detects thermal radiation emitted by the driver and front passenger seat occupants and surroundings and converts its data into a linear Pulse Width Modulated (PWM) output signal which is read by the Automatic Temperature Control (ATC) A/C-heater control. The ATC A/C-heater control uses the infrared sensor data as one of the inputs necessary to automatically control the interior cabin temperature levels. By using thermal radiation (surface temperature) measurement, rather than an air temperature measurement, the ATC heating-A/C system is able to adjust itself to the comfort level as perceived by the occupants. This allows the ATC system to compensate for other ambient conditions affecting comfort levels, such as solar heat gain or evaporative heat loss.

The ATC system logic responds to the infrared sensor message by calculating and adjusting the air flow temperature and air flow rate needed to properly obtain and maintain the selected comfort level temperature of the occupants. The A/C-heater control continually monitors the infrared sensor circuits, and will store Diagnostic Touble Codes (DTCs) for any problem it detects.

The infrared sensor is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The infrared sensor cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Scheme 10

1. Disconnect and isolate the negative battery cable.
2. Using Trim Stick C-4755 or equivalent, carefully disengage the four retaining tabs (1) that secure the infrared sensor and overhead map/courtesy lamp bezel (2) to the overhead console (3).
3. Disconnect the wire harness connectors (4) from the two overhead map/courtesy lamps (5) and the infrared sensor (6) and remove the sensor, lamp and bezel assembly from the vehicle

The ATC dual-zone heating-A/C system uses two sun sensors to balance the system in response to side-to-side variations in sun light intensity. Passengers in sun and shadow require different functional settings because they experience very different temperatures. The sun sensor assembly provides data to the A/C heater control to help determine proper mode and blend-air door positions and blower motor speeds. The sun sensors are not thermistor type sensors, but rather photo diodes. For this reason the sun sensors responds to sun light intensity rather than temperature. The sun sensor assembly is also used to sense day and night conditions for automatic headlight control, if equipped.

The sun sensor is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The sun sensor assembly cannot be adjusted or repaired and must be replaced if inoperative or damaged.

The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection to a fitting on the A/C discharge line. The internal resistance of the A/C pressure transducer changes in response to the pressures it monitors.

The Totally Integrated Power Module (TIPM) provides a five volt reference signal and a sensor ground to the A/C pressure transducer. The TIPM then monitors the output voltage of the transducer on a sensor return circuit to determine refrigerant pressure and sends a message to the Powertrain Control Module (PCM) or the Engine Control Module (ECM) (depending on engine application) over the CAN C BUS.

With 2.7L/3.5L 5-Passenger and all 7-Passenger models, the PCM is programmed to respond to this and other sensor inputs by controlling the operation of the swash plate within the A/C compressor and the radiator cooling fan to help optimize A/C system performance and to protect the system components from damage. The PCM adjusts the swash plate to nearly a zero degree angle (low compressor displacement) when high side pressure rises above 3130 kPa (454 psi) and readjusts the swash plate to a greater angle (higher compressor displacement) when high side pressure drops below 1999 kPa (290 psi). The A/C pressure transducer also reduces the swash plate angle if the high side pressure drops below 200 kPa (29 psi) and will increase the swash plate angle when the high side pressure rises above 234 - 262 kPa (34 - 38 psi). When the refrigerant pressure rises above 1655 kPa (240 psi), the PCM will actuate the cooling fan.

With 2.0L/2.4L 5-Passenger models, A/C compressor clutch engagement is controlled by the PCM or ECM, depending on engine application. When the A/C-heater control is set to any A/C position, it sends a request signal on the CAN-IHS bus to the TIPM, which then transfers the request on the CAN-C Bus to the PCM/ECM, which determines if operating conditions are correct for A/C clutch engagement. When all operating conditions have been met, the PCM/ECM sends a signal on a dedicated hard-wired circuit back to the TIPM to energize the internal A/C clutch high side driver. When energized, the A/C clutch high side driver provides battery current to the A/C clutch field coil.

A Schrader-type valve in the A/C discharge line fitting permits the A/C pressure transducer to be removed or installed without disturbing the refrigerant in the A/C system.

The A/C pressure transducer is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Diagnosis and Testing .

The A/C pressure transducer cannot be adjusted or repaired and must be replaced if inoperative or damaged.

The rear blend door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the rear heater-A/C wire harness. The rear blend door actuator can move the rear blend-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the rear blend-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the rear blend-air door moves in the opposite direction. When the front A/C-heater control makes the voltage to both connections high or both connections low, the rear blend-air door stops and will not move.

The front A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the rear blend door actuator and the rear blend-air door. The front A/C-heater control learns the rear blend-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the rear blend door actuator circuits.

The rear blend door actuator is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The rear blend door actuator cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Scheme 11

1. Disconnect and isolate the negative battery cable.
2. Remove rear heater-A/C housing (4) and place it on a workbench. See «Heating and Air Conditioning/Distribution/HOUSING, HVAC - Removal»(ref-353571-S29064437382010011200000) .
3. Disconnect the wire harness connector (3) from the rear blend door actuator (2) located on the outboard side of the rear heater-A/C housing.
4. Remove the two screws (1) that secure the rear blend door actuator to the rear heater-A/C housing and remove the actuator.

Scheme 12

1. Position the rear blend door actuator (1) onto the rear heater-A/C housing (3). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those on the rear blend-air door pivot shaft (2).
2. Install the two screws (1) that secure the rear blend door actuator (2) to the rear heater-A/C housing (4). Tighten the screws to 1.2 N.m (10 in. lbs.).
3. Connect the wire harness connector (3) to the rear blend door actuator.
4. Install the rear heater-A/C housing. See «Heating and Air Conditioning/Distribution/HOUSING, A/C and Heater - Installation»(ref-353571-S04147805512010011200000) .
5. Initiate the Actuator Calibrationfunction using a scan tool. Refer to «DTC-Based Diagnostics/HVAC - Standard Procedure»(ref-353597-S10593984932010011200000) .

The mode door actuator (1) for the rear heater-A/C system is a reversible, 12 volt direct current (DC), servo motor. The rear mode door actuator is located on the outboard side of the rear heater-A/C housing.

The rear mode door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2), an output shaft with splines (3) connect it to the rear mode-air door and three integral mounting tabs (4) allow the actuator to be secured to the rear heater-A/C housing. The mode door actuator does not require mechanical indexing to the mode door linkage, as it is electronically calibrated by the A/C-heater control.

The A/C-heater control must be recalibrated each time an actuator motor is replaced. Refer to DTC-Based Diagnostics/HVAC - Standard Procedure .

The rear mode door actuator is interchangeable with the actuator for the rear blend-air door.

The rear mode door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the rear heater-A/C wire harness. The rear mode door actuator can move the rear mode-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the rear mode-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the rear mode-air door moves in the opposite direction. When the front A/C-heater control makes the voltage to both connections high or both connections low, the rear mode-air door stops and will not move.

The front A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the rear mode door actuator and the rear mode-air door. The front A/C-heater control learns the rear mode-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the rear mode door actuator circuits.

The rear mode door actuator is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The rear mode door actuator cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Scheme 13

1. Disconnect and isolate the negative battery cable.
2. Remove rear heater-A/C housing (3) and place it on a workbench. See «Heating and Air Conditioning/Distribution/HOUSING, HVAC - Removal»(ref-353571-S29064437382010011200000) .
3. Disconnect the wire harness connector (4) from the rear mode door actuator (2) located on the outboard side of the rear heater-A/C housing.
4. Remove the two screws (1) that secure the rear mode door actuator to rear heater-A/C housing and remove the actuator.

Scheme 14

1. Position the rear mode door actuator (1) onto the rear heater-A/C housing (3). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those on the rear mode-air door pivot shaft (2).
2. Install the two screws (1) that secure the rear mode door actuator (2) to the rear heater-A/C housing (3). Tighten the screws to 1.2 N.m (10 in. lbs.).
3. Connect the wire harness connector (4) to the rear mode door actuator.
4. Install the rear heater-A/C housing. See «Heating and Air Conditioning/Distribution/HOUSING, A/C and Heater - Installation»(ref-353571-S04147805512010011200000) .
5. Initiate the Actuator Calibration function using a scan tool. Refer to «DTC-Based Diagnostics/HVAC - Standard Procedure»(ref-353597-S10593984932010011200000) .

The A/C-heater controls allows the driver and front seat passenger and the intermediate seat passengers the ability to regulate air temperature as well as fan speed for the rear heating-A/C system and provides a floor outlet near the right rear door and upper air outlets at the ceiling. All controls are identified by ISO graphic symbols.

The primary controls for the rear heating-A/C system are located in the instrument panel. See Heating and Air Conditioning/Controls/CONTROL, A/C and Heater - Description .

The rear A/C-heater control is located in the headliner and allows intermediate seat passengers to adjust rear air distribution, temperature and blower motor speed when the rear heating-A/C system primary on/off control in the instrument panel is set to the on position and the rear heater-A/C controls are NOT locked out by the driver and front seat passenger.

The rear automatic temperature control (ATC) A/C-heater control (1) contains

1. a rotary control knob for fan speed selection and turning the rear heating-A/C system off or to Auto mode (2).
2. a rotary control knob for temperature control of the rear discharged air (3). An indicator lamp illuminates in the control when the rear heater-A/C controls are locked out by the driver or front seat passenger.
3. a rotary control knob for mode control of the rear discharged air (4).

The rear manual temperature control (MTC) A/C-heater control (1) contains

1. a rotary control knob for fan speed selection and turning the rear heating-A/C system on and off (2).
2. a rotary control knob for temperature control of the rear discharged air (3). An indicator lamp illuminates in the control when the rear heater-A/C controls are locked out by the driver or front seat passenger.
3. a rotary control knob for mode control of the rear discharged air (4).

The rear A/C-heater control is a slave potentiometer to the front A/C-heater control and is diagnosed using a scan tool (refer to HEATING & AIR CONDITIONING (ATC) - ELECTRICAL DIAGNOSTICS or HEATING & AIR CONDITIONING (MTC) - ELECTRICAL DIAGNOSTICS ).

Prior to replacing an A/C-heater control, check for any diagnostic trouble codes (DTCs) related to the heating-A/C systems and run the calibration procedure to verify that the concern is not a system issue. Refer to DTC-Based Diagnostics/HVAC - Standard Procedure .

The rear A/C-heater control cannot be repaired must be replaced if inoperative or damaged. The illumination lamps are available for service replacement.

The rear blower motor power module is connected to the vehicle electrical system through a dedicated lead and connector of the rear body wire harness. A second lead and connector of the wire harness is connected to the rear blower motor. The rear blower motor power module allows the microprocessor-based automatic temperature contro (ATC) A/C-heater control to calculate and provide infinitely variable blower motor speeds based upon either manual blower switch input or the ATC programming using a pulse width modulated (PWM) circuit strategy.

The PWM voltage is applied to a comparator circuit which compares the PWM signal voltage to the rear blower motor feedback voltage. The resulting output drives the power module circuitry, which provides a linear output voltage to change or maintain the desired blower speed.

The rear blower motor power module is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The rear blower motor power module cannot be adjusted or repaired must be replaced if inoperative or damaged.

Scheme 15

1. Disconnect and isolate the negative battery cable.
2. Remove right rear quarter trim panel. Refer to «Body/Interior/PANEL, Quarter Trim - Removal»(ref-353577-S13349045142010011200000) .
3. Disconnect the two wire harness connectors (4) from the rear blower motor power module (3).
4. Remove the two screws (1) that secure the rear blower motor power module to the rear heater-A/C housing (2) and remove the module.

The blower motor resistor for the rear heating-A/C system is connected to the vehicle electrical system through a dedicated wire lead and connector of the rear heater-A/C wire harness. The rear blower motor resistor has an electrical circuit board with three resistors, each of which will reduce the current flow through the rear blower motor to change the blower motor speed.

The blower motor switch for the MTC rear heater-A/C system directs the ground path for the rear blower motor through the correct resistor to obtain the selected speed. With the rear blower motor control in the lowest speed position, the ground path for the rear blower motor is applied through all of the resistors. Each higher speed selected with the rear blower motor control applies the blower motor ground path through fewer of the resistors, increasing the rear blower motor speed. When the blower motor switch is in the highest speed position, the blower motor resistors are bypassed and the blower motor receives a direct path to ground through the rear blower motor switch.

The rear blower motor resistor cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

The blower motor controls the velocity of air moving through the HVAC housing by spinning the blower wheel within the HVAC air inlet housing at the selected speed.

On the Manual Temperature Control (MTC) heating-A/C system, blower motor speed is controlled by regulating the path to ground through the blower control switch and the blower motor resistor. With the Automatic Temperature Control (ATC) heating-A/C system, blower motor speed is controlled by an electronic blower motor power module, that uses a Pulse Width Modulated (PWM) input from the A/C-heater control and a feedback signal from the blower motor to regulate the blower motor ground path. On both systems, the blower motor receives battery current through the Totally Integrated Power Module (TIPM) whenever the ignition switch is in the Run position, and the blower motor control is in any position except Off.

The blower motor can be accessed for service from underneath the instrument panel.

Note. The blower motor is supplied with a 12 volt feed from the TIPM whenever the ignition switch is in the Run position. Due to an open circuit condition within the blower motor control switch, the TIPM is unable to detect an open circuit for the blower motor.

The blower motor control system is diagnosed using a scan tool. Refer to DTC-Based Diagnostics/HVAC - Diagnosis and Testing .

The blower motor and blower motor wheel are factory balanced as an assembly and cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Possible causes of an inoperative blower motor include

1. Open fuse
2. Inoperative blower motor resistor
3. Inoperative blower motor switch
4. Inoperative blower motor
5. Inoperative blower motor circuit wiring or wire harness connectors

Models with the rear heating-A/C system use a rear heater-A/C housing (1) that combines A/C and heating capabilities into a single unit mounted within the rear passenger compartment. The rear heating-A/C system is a blend-air type system. A blend-air door controls the amount of conditioned air that is allowed to flow through, or around, the heater core (9). The rear A/C system is designed for the use of a non-CFC, R-134a refrigerant and uses an A/C expansion valve (7) and A/C evaporator (6) to cool and dehumidify the incoming air prior to blending it with the heated air. A temperature control determines the discharge air temperature by operating the blend door actuator (3), which moves the blend-air door. This allows an almost immediate control of the output air temperature of the rear system. The mode control operates the mode door actuator (2) that positions the mode-air door to direct the flow of the conditioned air out the upper or lower air outlets, depending on the position selected. Both electric door actuators are connected to the vehicle electrical system by the rear heater-A/C wire harness (8). The rear blower motor (4) controls the velocity of air flowing through the rear heater-A/C housing by spinning the blower wheel within the rear housing at the selected speed by use of the rear blower motor resistor or power module (5) (depending on manual or automatic control).

The rear heater-A/C housing must be removed from the vehicle for service of the mode door actuator and blend door actuator and it must be disassembled for service of the A/C evaporator and the heater core.

The rear blower motor is used to control the velocity of air moving through the rear heater-A/C housing by spinning the blower wheel within the heater-A/C housing at the selected speed.

The rear blower motor will only operate when the ignition switch is in ON and the rear blower motor switch located in the front accessory switch panel is ON. The rear blower motor receives a battery feed through the totally integrated power module (TIPM), whenever the ignition switch is in ON. See Heating and Air Conditioning/Distribution/MOTOR, Blower - Diagnosis and Testing .

The rear blower motor and blower wheel are factory balanced and cannot be adjusted or repaired and must be replaced as an assembly if inoperative or damaged.

Scheme 16

1. Disconnect and isolate the negative battery cable.
2. Remove right rear quarter trim panel. Refer to «Body/Interior/PANEL, Quarter Trim - Removal»(ref-353577-S13349045142010011200000) .
3. Disconnect the wire harness connector (3) from the rear blower motor (1).
4. Disengage the locking tab (4) and remove the rear blower motor from the rear heater-A/C housing (2) by turning the blower motor counterclockwise.

Scheme 17

1. Position the rear blower motor (1) into the rear heater-A/C housing (2) and rotate the blower motor clockwise until the blower motor is fully engaged to the housing and the retaining tab (4) is in the locked position.
2. Connect the wire harness connector (3) to the rear blower motor.
3. Install the right rear quarter trim panel. Refer to «Body/Interior/PANEL, Quarter Trim - Installation»(ref-353577-S36809696592010011200000) .
4. Reconnect the negative battery cable.

Scheme 18

1. Rotate the air outlet (1) being serviced clockwise until the retaining tabs on the back of the outlet disengage from the headliner (2).
2. Remove the air outlet from the headliner.

Scheme 19

1. Position the air outlet (1) being serviced to the opening in the headliner (2).
2. Rotate the air outlet counterclockwise until the retaining tabs on the back of the outlet are fully engaged to the headliner.

The A/C refrigerant lines and hoses are used to carry the refrigerant between the various A/C system components. The refrigerant lines and hoses for the R-134a A/C system consist of a barrier-hose design with a nylon tube sandwiched between rubber layers. The nylon tube helps to contain the R-134a refrigerant, which has a small molecular structure. The ends of the refrigerant lines are made from lightweight aluminum and brazed fittings.

Any kinks or sharp bends in the refrigerant lines and hoses will reduce the capacity of the entire A/C system and can reduce the flow of refrigerant within the system.

High pressures are produced in a refrigerant system when the A/C compressor is operating. Extreme care must be exercised to make sure that each of the refrigerant system connections is pressure-tight and leak free. It is a good practice to inspect all flexible hose refrigerant lines at least once a year to make sure they are in good condition and properly routed.

Depending on vehicle, model and market application, refrigerant lines are connected to each other or other A/C system components with block-type or quick-connect type fittings. To ensure the integrity of the refrigerant system, O-rings and/or gaskets may be used to seal the refrigerant system connections.

The refrigerant lines and hoses cannot be repaired and must be replaced if leaking or damaged.

When air passes through the fins of the A/C condenser, the high-pressure refrigerant gas within the A/C condenser gives up its heat. The refrigerant then condenses as it leaves the A/C condenser and becomes a high-pressure liquid. The volume of air flowing over the condenser fins is critical to the proper cooling performance of the A/C system. Therefore, it is important that there are no objects placed in front of the radiator grille openings at the front of the vehicle or foreign material on the condenser fins that might obstruct proper air flow. Also, any factory-installed air seals or shrouds must be properly reinstalled following radiator or A/C condenser service.

Note. Replacement of the refrigerant line O-ring seals and gaskets is required anytime a refrigerant line is disconnected. Failure to replace the rubber O-ring seals and metal gaskets could result in a refrigerant system leak.

The A/C condenser has no serviceable parts. The O-ring seals used on the connections are made from a special type of rubber not affected by R-134a refrigerant. The O-ring seals and gaskets must be replaced whenever a refrigerant line is disconnected from the A/C condenser.

The A/C condenser cannot be repaired and must be replaced if leaking or damaged.

Note. LHD model shown. RHD model similar.

Scheme 20

The heater core (1) for the heating-A/C system is mounted within the HVAC air distribution housing, which is located behind the instrument panel. The heater core is a heat exchanger made of rows of tubes with fins and is positioned within the air distribution housing so that only the selected amount of air entering the housing passes through the heater core before it is distributed through the heating-A/C system ducts and outlets. One end of the heater core is fitted with a tank (2) that includes the fittings for the heater core tubes (3).

The heater core can only be serviced by removing the HVAC housing from the vehicle.

Engine coolant is circulated through the heater hoses to the heater core at all times. As the coolant flows through the heater core, heat is removed from the engine and is transferred to the heater core tubes and fins. Air directed through the heater core picks up the heat from the heater core fins. The blend-air door allows control of the heater output air temperature by regulating the amount of air flowing through the heater core. The blower motor speed controls the volume of air flowing through the HVAC housing.

The heater core cannot be repaired and it must be replaced if inoperative, leaking or damaged.

Refrigerant system service ports are used to recover, recycle, evacuate, charge and test the A/C refrigerant system. Unique sizes are used on the two service ports for the R-134a refrigerant system to ensure the system is not accidentally contaminated with R-12 refrigerant or by service equipment used for R-12 refrigerant.

The high side service port is located on the A/C liquid line near the right front strut tower. The low side service port is located on the A/C suction line near the dash panel.

Both the high side and low side A/C service port valve cores are serviceable.

Note. The protective cap aids in service port sealing and helps protect the refrigerant system from contamination. Remember to always reinstall the protective caps onto the service ports when refrigerant system service is complete.

Each of the service ports has a threaded plastic protective cap installed over it from the factory. The service port caps are serviceable items.

The A/C receiver/drier performs a filtering action to prevent foreign material in the refrigerant from contaminating the A/C expansion valve. Refrigerant enters the A/C receiver/drier as a high-pressure, low temperature liquid. Desiccant inside the A/C receiver/drier absorbs any moisture which may have entered and become trapped within the refrigerant system. In addition, during periods of high demand operation of the A/C system, the A/C receiver/drier acts as a reservoir to store surplus refrigerant.

Note. Replacement of the refrigerant line O-ring seals and gaskets is required anytime a refrigerant line is disconnected. Failure to replace the rubber O-ring seals and metal gaskets could result in a refrigerant system leak.

The A/C receiver/drier has no serviceable parts except for the O-ring seals and gaskets. The O-ring seals used on the connections are made from a special type of rubber not affected by R-134a refrigerant. The O-ring seals and gaskets must be replaced whenever the A/C receiver/drier is disconnected.

The A/C receiver/drier cannot be repaired and must be replaced if leaking or damaged, or if an internal failure of the A/C compressor has occurred.

Refrigerant enters the A/C evaporator from the A/C expansion valve as a low-temperature, low-pressure mixture of liquid and gas. As air flows over the fins of the A/C evaporator, the humidity in the air condenses on the fins, and the heat from the air is absorbed by the refrigerant. Heat absorption causes the refrigerant to boil and vaporize. The refrigerant becomes a low-pressure gas when it leaves the A/C evaporator.

Note. Replacement of the refrigerant line O-ring seals and gaskets is required anytime a refrigerant line or expansion valve is disconnected. Failure to replace the rubber O-ring seals and metal gaskets could result in a refrigerant system leak.

The A/C evaporator has no serviceable parts except for the O-ring seals. The O-ring seals used on the connections are made from a special type of rubber not affected by R-134a refrigerant. The O-ring seals must be replaced whenever the A/C expansion valve is removed from the A/C evaporator.

The A/C evaporator cannot be repaired and must be replaced if leaking or damaged.

The refrigerant oil used in R-134a refrigerant systems is a synthetic-based, polyalkylene glycol (PAG), wax-free lubricant. Mineral-based R-12 refrigerant oils are not compatible with PAG oils and should never be introduced to an R-134a refrigerant system.

There are different PAG oils available and each contain a different additive package. Always use only the type of refrigerant oil recommended for the A/C compressor in the vehicle.

The A/C compressors used in this vehicle is designed to use ND-8 PAG refrigerant oil. Use only this type of refrigerant oil in the refrigerant system.

After performing any refrigerant recovery or recycling operation, always replenish the refrigerant system with the same amount of the recommended refrigerant oil as was removed. Too little refrigerant oil can cause A/C compressor damage, and too much can reduce A/C system performance.

PAG refrigerant oil is more hygroscopic than mineral oil, and will absorb any moisture it comes into contact with, even moisture in the air. The PAG oil container should always be kept tightly capped until it is ready to be used. After use, recap the oil container immediately to prevent moisture contamination.

The refrigerant used in this air conditioning system is a HydroFluoroCarbon (HFC), type R-134a. Unlike R-12, which is a ChloroFluoroCarbon (CFC), R-134a refrigerant does not contain ozone-depleting chlorine. R-134a refrigerant is a non-toxic, non-flammable, clear, and colorless liquefied gas.

Even though R-134a does not contain chlorine, it must be reclaimed and recycled just like CFC-type refrigerants. This is because R-134a is a greenhouse gas and can contribute to global warming. See Heating and Air Conditioning/Plumbing - Standard Procedure .

R-134a refrigerant is not compatible with R-12 refrigerant in an A/C system. Even a small amount of R-12 refrigerant added to an R-134a refrigerant system will cause A/C compressor failure, refrigerant oil sludge or poor A/C system performance. In addition, the polyalkylene glycol (PAG) synthetic refrigerant oils used in an R-134a refrigerant system are not compatible with the mineral-based refrigerant oils used in an R-12 refrigerant system.

R-134a refrigerant system service ports, service tool couplers and refrigerant dispensing bottles have all been designed with unique fittings to ensure that an R-134a refrigerant system is not accidentally contaminated with the wrong refrigerant (R-12). There are also labels posted in the engine compartment of the vehicle and on the A/C compressor to identify that the A/C system is equipped with R-134a refrigerant.

The A/C expansion valve controls the high-pressure, low temperature liquid refrigerant from the A/C liquid line and converts it into a low-pressure, low-temperature mixture of liquid and gas before it enters the A/C evaporator. A mechanical sensor in the A/C expansion valve monitors the temperature and pressure of the refrigerant leaving the A/C evaporator through the A/C suction line, and adjusts the orifice size at the liquid line port to let the proper amount of refrigerant into the evaporator to meet the vehicle A/C cooling requirements. Controlling the refrigerant flow through the A/C evaporator ensures that none of the refrigerant leaving the A/C evaporator is still in a liquid state, which could damage the A/C compressor.

Note. Replacement of the refrigerant line O-ring seals is required anytime a refrigerant line is disconnected from the expansion valve, or if the expansion valve is removed. Failure to replace the rubber O-ring seals may result in a refrigerant system leak.

The A/C expansion valve is factory calibrated and cannot be adjusted or repaired and must be replaced if inoperative or damaged.

Engine coolant is circulated through heater hoses and tubes to the rear heater core at all times. As the coolant flows through the heater core, heat removed from the engine is transferred to the heater core fins and the air directed through the heater core picks up the heat from the fins. The rear blend-air door allows control of the rear heater output air temperature by controlling the amount of air flowing through or around the rear heater core. The rear blower motor speed controls the volume of air flowing through the rear heater-A/C housing.

The rear heater core cannot be repaired and must be replaced if inoperative, leaking or damaged.

Refrigerant enters the rear A/C evaporator from the rear A/C expansion valve as a low-temperature, low-pressure mixture of liquid and gas. As air flows over the fins of the rear A/C evaporator, the humidity in the air condenses on the fins, and the heat from the air is absorbed by the refrigerant. Heat absorption causes the refrigerant to boil and vaporize. The refrigerant becomes a low-pressure gas when it leaves the rear A/C evaporator.

Note. Replacement of the refrigerant line O-ring seals is required anytime a refrigerant line or expansion valve is disconnected. Failure to replace the rubber O-ring seals could result in a refrigerant system leak.

The A/C evaporator has no serviceable parts except for the O-ring seals. The O-ring seals used on the connections are made from a special type of rubber not affected by R-134a refrigerant. The O-ring seals must be replaced whenever the rear A/C expansion valve is removed from the rear A/C evaporator.

The rear A/C evaporator cannot be repaired and must be replaced if leaking or damaged.

The rear A/C expansion valve controls the amount of refrigerant entering the rear A/C evaporator. The rear A/C expansion valve is of a thermostatic expansion valve (TXV) design and consists of an aluminum H-valve type body (1) with an inlet port (2), outlet port (3) and an integral thermal sensor (4).

The rear A/C expansion valve is located on the bottom of the rear heater-A/C housing, which extends through the rear floor panel behind the right rear wheel housing.

The rear A/C expansion valve controls the flow of high-pressure, low temperature liquid refrigerant entering the expansion valve and converts it into a low-pressure, low-temperature mixture of liquid and gas before it enters the rear A/C evaporator. To meet the vehicles A/C cooling requirements, a mechanical sensor is used in the rear A/C expansion valve to monitor the temperature and pressure of the refrigerant leaving the rear A/C evaporator and then adjust the inlet port orifice size to allow only the proper amount of refrigerant to enter the evaporator. Controlling the refrigerant flow through the rear A/C evaporator ensures that none of the refrigerant leaving the evaporator is still in a liquid state, which could damage the A/C compressor.

Note. Replacement of the refrigerant line O-ring seals is required anytime a refrigerant line is disconnected from the expansion valve, or if the expansion valve is removed. Failure to replace the rubber O-ring seals may result in a refrigerant system leak.

The rear A/C expansion valve is factory calibrated and cannot be adjusted or repaired and must be replaced if inoperative or damaged. See Heating and Air Conditioning/Plumbing/VALVE, A/C Expansion - Diagnosis and Testing .

The three ISO-standard relays (1) used for the electric positive temperature coefficient (PTC) heater system are electromechanical switches that use a low current ASD power input to control the high current fused battery power output to the PTC heater unit. On each relay, the movable, common feed relay contact is held against the fixed, normally closed relay contact by spring pressure. When the electromagnetic relay coil is energized, it draws the movable common feed relay contact away from the fixed, normally closed relay contact and, holds it against the fixed, normally open relay contact. This action allows high current to flow to one or more of the heating elements of the PTC heater.

When the relay coil is de-energized, spring pressure returns the movable relay contact back against the fixed, normally closed contact point. The resistor or diode is connected in parallel with the relay coil, and helps to dissipate voltage spikes and electromagnetic interference that can be generated as the electromagnetic field of the relay coil collapses.

The terminals for the PTC relays are connected to the vehicle electrical system through receptacles in the diesel accessory fuse/relay block. Refer to SYSTEM WIRING DIAGRAMS for inputs and outputs of the PTC relays.

The PTC relays cannot be repaired and must be replaced if inoperative or damaged. See SYSTEM WIRING DIAGRAMS for diagnosis and testing of the ISO-standard relays and for complete TIPM and HVAC wiring diagrams.

Scheme 21

Note. LHD model shown. RHD model similar.

1. Disconnect and isolate the negative battery cable.
2. Remove the cover from the diesel accessory fuse/relay block (1) located near the left front strut tower.
3. Remove the positive temperature coefficient (PTC) relays (2) as necessary from the fuse/relay block.

The positive temperature coefficient (PTC) heater unit dissipates 1 kW of electrical power through three heating elements. The PTC heater unit is split into three "banks". Each bank (element) is driven separately based on alternator load. This allows for lower in-rush current and optimum battery charging. After a bank has been turned on, another bank can only be turned on 10 seconds after the previous. On average, the PTC banks are not switched more than 25 times for each vehicle start. Electrical power output is between 900-1050 W. The totally integrated power module (TIPM) operates three relays for the PTC heater unit. See Heating and Air Conditioning/Cabin Heater/RELAY, Heater Unit - Description .

The control system for the PTC heater unit is diagnosed using a scan tool. Prior to replacing a PTC heater unit, check for any diagnostic trouble codes (DTCs) related to the ECM, TIPM and heating-A/C system.

The PTC heater unit cannot be adjusted or repaired must be replaced if inoperative or damaged.