Climate Units - Design and Function: Other Volvo S80 I

Evaporator

The heat from the incoming air is transferred to the refrigerant which converts to a gas. The following modifications are made by comparison with the S70/V70

1. Yellow chromating of the surface to prevent corrosion. A polyurethane coat to avoid bad odors. The polyurethane coating reduces the water surface tension which means that it runs off.
2. The drainage pipe with the collection plate is installed downstream of the evaporator and exits through the firewall.

Compressor

The following changes have been introduced by comparison with the compressor on the S70/V70

1. The same basic concept as the compressor but a larger cylinder displacement, 167 cm 3 higher capacity.
2. Maximum acceleration compressor disengagement for at least 10 seconds but a maximum of 20 seconds.

The starting process for the air conditioning compressor

If the engine coolant temperature (ECT) is warmer than -7°C, the air conditioning relay is controlled by the engine control module (ECM). This is so that the compressor engages every time the car is started. The compressor is engaged during the start process in exactly the same way as when the air conditioning (A/C) is selected.

1. Engagement occurs during the starting process regardless or not of whether the air conditioning (A/C) is selected or not.
2. Engagement continues for 100 engine revolutions. The compressor is then disengaged.
3. If the air conditioning (A/C) is selected, the compressor continues to be driven.

The starter motor has a lower engine speed (RPM) than the car engine. As a result, the pressure in the compressor is not as high. The risk of the safety valve being activated is eliminated and any liquefied refrigerant is driven out of the compressor.

Temperature sensor

The anti-freeze protection for the system consists of a temperature sensor. This measures the temperature of the airflow which has just passed the evaporator. The sensor has a capacity controlling function. This switches the compressor on/off to prevent condensation freezing. The following modifications have been introduced.

1. The sensor is located downstream of the evaporator. This makes it easier to install/replace the component.
2. The sensor transmits a signal to the climate control system. The climate control system transmits the signal on to the engine control module (ECM). The ECM regulates the switching on/off for the air conditioning relay. The A/C relay switches off the compressor (at 4.0 - 6.9°C) and on (at 4.8 - 7.5°C). The control module can delay the engagement or temporarily disconnect the compressor under full acceleration.

Condenser

The refrigerant is cooled and condensed in the condenser. The refrigerant fluid continues to the drier unit in the refrigerant reservoir.

Receiver drier

To facilitate any leak tracing, a fluorescent agent is added to the receiver drier at the factory. This mixes with the system oil during operation.

Service valves

The air conditioning must be filled with 1000 grams of refrigerant. Refrigerant may only be topped up on the high pressure side of the system. This is to avoid the risk of liquid refrigerant entering the compressor. The valves are different sizes. This is to avoid incorrect connection. The service valves can be used for

1. Checking through the manometer connections.
2. Draining the refrigerant from both valves.
3. Evacuating/vacuum cleaning through both valves.
4. Filling with refrigerant on the high pressure side.

Note. Refrigerant may only be topped up on the high pressure side of the system. This is to avoid the risk of refrigerant entering the compressor.

TEV

The valve is a pressure and temperature dependent block type flow regulator. If there is a low cooling requirement, the amount of coolant is reduced by closing the valve. If the amount of cooling increases, the valve will open slightly. This allows more fluid into the evaporator.

The thermostatic expansion valve (TEV) has a larger register than a system with a fixed choke. This is because the refrigerant volume can be more accurately controlled according to the cooling requirements.

Linear pressure sensor

The linear pressure sensor is installed directly on the receiver drier. The pressure sensor has an integrated measurement amplifier. This provides an output voltage which is linear to the pressure (0-35 bar). The signal is used to control the following functions

1. The engine cooling fan (FC).
2. Compressor disengagement at high pressure (> 30 bar).
3. Compressor disengagement if the system is completely empty (< 1.76 bar).

The pressure sensor cannot be replaced without draining the system first.

Thermo Switch

The thermo switch switches off the compressor when the material temperature exceeds 135°C. It switches on again when the temperature is below 120°C. It switches off to prevent the compressor seizing.

Normally this material temperature occurs only in the following combination of circumstances

1. Low refrigerant level.
2. The vehicle speed is > 70 km/h.
3. The outside temperature is > 30-35°C.

Scheme 347

The different air vents

Air enters the passenger compartment and is distributed through a large number of air vents. The temperature of the air from all the air vents can be controlled separately for left and right hand sides.

Defroster openings

The openings for the windshield defroster guide the air onto the windshield to rapidly warm and demist it. The front door windows will also be demisted by the two openings for the side defroster openings.

Ventilation openings

The openings give the possibility of guiding the air in a specific direction and can be shut separately. There are four large openings on the dashboard and two smaller ones on the B posts.

Floor openings

There are separate floor openings for the front and rear areas. In the front they are to the left and right of the center console. In the rear they are underneath the driver and passenger seats.

Evacuation channels

The channels for evacuating the air in the passenger compartment are in the rear section of the parcel shelf.

Note. These must not be blocked, it will lead to the climate control system function being reduced. The channels lead off the air to the cargo compartment where the air is evacuated through check valves with rubber lips which are opened by overpressure.

Scheme 348

Heater element

The engine coolant flows through the heater element constantly. There is no valve to regulate the flow. The set temperatures are achieved by shutters for the right and left hand sides installed upstream of the heater element. The control the amount of air to be warmed. There is also shutters downstream of the heater element that guide the airflow to the correct air vent.

Blower fan in the passenger compartment

All the systems have stepless electronic blower fan control. When AUTO (Electronic climate control (ECC) is engaged the Climate control module regulates the blower fan speed to the control setting and the vehicle speed.

The blower fan speed is adjusted to the vehicle speed up to 160 km/h (99 mph) at which point the fan stops. At higher speeds the air intake is adjusted by the fresh air shutter.

Before the fan starts the Climate control module runs a diagnostic check. This is carried out by the power unit supplying the fan with 12.5 volts for 0.3 second and then with 6.5 volts for another 2.7 seconds. The 0.3 seconds long supply pulse has the task of overcoming the resistance of any ice or snow that may otherwise block the fan wheel, at the same time the diagnostic whether the fan is blocked. In the next 2.7 seconds the fan power consumption is measured. After the diagnostic check the fan gradually returns to the selected speed.

Blower fan run on

Blower fan run on reduces the amount of water remaining in the evaporator.

Run on is time governed and controlled by a timer located in the central electronic module (CEM) which ensures that power supply to the Climate control module is activated for 50 minutes after the ignition has been turned to positions 0 or I. This means that the Climate control module is put in the run on position and starts a check program to dry out the evaporator. Run on is activated for 7 minutes.

The function is only activated as a result of a customer complaint. Activation is carried out by programming customer parameters via VIDA.

Particle filter

The particle filter is standard and is mounted downstream of the blower fan so that even recirculated air is cleaned. The particle filter should be replaced every 15,000 km or 2 years. The particle filter was previously available as an option or as standard (market dependent), but then mounted at the air intake. This meant that recirculated air was not cleaned.

Shutter motors

The Manual climate control (MCC) and standard (STD) systems previously had cables between the air distribution controls and the floor, defroster and ventilation shutters. The manual system is now replaced by the same type of controls used on the Electronic climate control (ECC).

1. All shutter motors are the stepper type, which means that angle of turn and speed is controlled electronically. Ventilation/floor/defroster via a link system. Recirculation and fresh air via a link system. Temperature left. Temperature right.
2. Manual climate control (MCC)/standard (STD) has 4 stepper motors which control the following shutters: Ventilation/floor/defroster via a link system. Recirculation and fresh air via a link system. Temperature left. Temperature right.
3. A stepper motor controlling the defroster is introduced on the Electronic climate control (ECC).

Stepper motor

Previously DC motors were used. The advantages with the stepper motors used is that

1. The stepper motor has no carbon which wears.
2. No sensor is required to determine shutter position.
3. The turning degree of the motor is determined by the number of control steps from the.
4. The stepper motor has a higher holding torque.

The wiring between the stepper motors and the Climate control module consists of 4 cables for supply voltage and direction control and a separate cable for each motor which controls which motor is to be activated.

In a DC motor the length of time a motor is supplied with power determines how many revolutions the motor shaft turns. In a stepper motor it is the number of control steps from the Climate control module. Only when the motor goes to an end position is the number of steps of no importance. The stepper motor are self-adjusting.

Scheme 349

Shutters

There are eleven different shutters which direct climate control unit air flow

1. Six temperature shutter for mixing hot and cold air. Three on the lefty and three in the right hand sides. On each side there is one shutter installed (2) upstream and one downstream (3) of the heater element. (1) and (2) together control the amount of air to be heated and (3) guides the hot air to the correct air vent.
2. A floor shutter for guiding the air flow to the front and rear.
3. A defroster shutter for guiding the air flow to the front windshield and side winders. NOTE: Electronic climate control (ECC) has a separate shutter motor for this shutter.
4. A ventilation shutter for guiding the air flow to the dashboard and B post.
5. A fresh air shutter for guiding outside air flow into the climate control system.
6. A recirculation shutter for guiding the air in the passenger compartment flow back into the climate control system.

Timed recirculation

There is a time limit which is activated by software parameters. Parameters are set in the factory or at after market installation.

If the Air conditioning (A/C) is manually activated (Electronic climate control (ECC), Manual climate control (MCC))

1. Recirculation is switched off after 5 minutes if outside temperature < 7°C (< 44.6°F).
2. Recirculation is switched off after 12 minutes if outside temperature is > 7°C (> 44.6°F).

If air conditioning is not activated or if AUTO is activated

1. Recirculation is switched off after 5 minutes if outside temperature < 7°C (< 44.6°F).
2. Recirculation is switched off after 12 minutes if outside temperature > 20°C (> 68°F).
3. Recirculation switches off according to a linear function if the outside temperature is between 7°C (44.6°F) and 20°C (68°F).

Speed compensation

When the vehicle speed is approximately 160 km/h (99 mph) the blower fan switches off. At higher speeds the intake air flow is controlled by the fresh air shutter closing. This reduces the risk of increased airflow into the passenger compartment. At approximately 190 km/h (118 mph) control ceases. The fresh air shutter is then completely closed.

If defroster is elected on the climate control panel speed compensation is deactivated if the vehicle speed exceeds 100 km/h (62 mph). The air is guided to the defroster vents and the fresh air shutter is fully opened. With automatic climate control the Climate control module calculates what position the shutters should be in order to satisfy the requirement.

Scheme 350

The Climate control module diagnostic system continuously diagnoses the function of the system components and stores any diagnostic trouble code (DTCs). The diagnostic trouble codes (DTCs) can then be read off via VIDA. The principles for presentation of information are the same as the cars other on-board diagnostic (OBD) system.

Diagnostic function is carried out automatically by the Climate control module or is activated by VIDA.

The diagnostic function is the same for all climate control systems (ECC/MCC/STD). The functions are the same while the in and output signals are dependent on the type of climate control.

The diagnostic function checks the sensors, stepper motors, blower fan, air conditioning system (ECC, MCC) and wiring.

The diagnostic function can be carried out when the climate control module has supply voltage. The Climate control module has this when the ignition key is in position II and for 50 minutes after the ignition has been switched off. (because of blower fan run on).

The identity of the Climate control module, and the installed software can be read off via the VIDA station.

Substitute value

The climate control system has built in substitute values which are activated automatically by the Climate control module when a fault on a certain component occurs. The Climate control module takes corrective action in case of faults in the following components

1. When there is a fault in the fan the Climate control module switches it off.
2. When there is a fault in the evaporator sensor the temperature is set to 0°C (32°F).
3. When there is a fault in the temperature sensor in the climate control panel the temperature is set to 22°C (71.6°F).
4. When there is a fault in the sun sensor a substitute value is set.
5. When there is a fault in the stepper motor it is taken out of function.

The Climate control module guides a return to normal function when the fault is remedied.

Input signals ECC/MCC/STD

Certain components are directly connected to the Climate control module and others are connected to other control modules in the network. The following signals are sent to the Climate control module regardless of the type of climate control system

1. Selected fan speed, air distribution, temperature and recirculation position from the climate control panel.
2. The vehicle speed signal from the ABS is used for speed compensation. The signal travels via the CEM.
3. Correction signal from the stepper motors when steps missing. The information updates the Climate control module about the motor position. When there is a fault in the stepper motor it is taken out of function.
4. Diagnostic signal about the blower fan power consumption from the power unit. When there is a fault in the fan the Climate control module switches it off.
5. Signals from VIDA via data link connector (DLC).

Input signals ECC/MCC

In addition to the common input signals the following signals are sent to the Climate control module when the system is an ECC or MCC

1. Air conditioning (A/C) selected from climate control panel. Climate control system pressure from the linear pressure sensor. Engine temperature from the engine coolant temperature (ECT) sensor.
2. The outside temperature comes either from the passenger door module (PDM) or drivers door module (DDM) depending on left or right hand drive because the temperature sensor is always on the right door mirror. Climate control system pressure from the linear pressure sensor. Engine temperature from the engine coolant temperature (ECT) sensor.
3. Fan control occurs in three stages, depending on the signal from the linear pressure sensor. Climate control system pressure from the linear pressure sensor. Engine temperature from the engine coolant temperature (ECT) sensor.
4. The engine control module (ECM) supplies the Climate control module with the following information (via the CEM): Climate control system pressure from the linear pressure sensor. Engine temperature from the engine coolant temperature (ECT) sensor.
5. The climate control system intake air temperature from the temperature sensor downstream of the evaporator. The signal is used to control the air conditioning (A/C) compressor. When there is a risk of freezing the compressor is switched off.

Input signals ECC

The following signals are specific for the Electronic climate control (ECC) climate control system

1. Sun roof open or closed from the Sun roof module (SRM). The sun roof position gives a signal for limiting the climate control. If the sun roof is opened on a warm summers day the blower fan is prevented from increasing speed to maximum speed to compensate for the temperature change.
2. The passenger compartment air temperature from the passenger compartment temperature sensor installed in the climate control panel.
3. The suns intensity from the sun sensor so that the Climate control module can adjust the air in the passenger compartment to the current sun conditions.
4. The steering wheel module supplies the Climate control module with the windshield wipers status to guide the air distribution to defrost to reduce the risk of misting on the windows in rain.

Scheme 351

The air conditioning unit in the Volvo P23 is different to the ones in the S70/V70. The major change is integration with the brand new network based electrical system where the CCM (Climate Control Module) controls the air conditioning unit.

Just like before, the climate control unit will be available in 3 versions

1. ECC , (Electronic Climate Control) which is a fully automated climate control unit with a cooler and manual setting options.
2. MCC , (Manual Climate Control) which is a manual climate control unit with cooler.
3. STD , (Standard Heater) which is a manual climate control unit without cooler.

When describing new features the S70/V70 climate control unit will be used as a comparison.

New features of climate control unit

Network module, CCM, which controls all climate functions. The CCM is integrated with the climate panel.

A particle filter is installed after the fan as standard to purify also recirculated air.

The ECC has five electronically controlled shutter valve motors (stepping motors). The MCC/STD has four.

The speed compensation closes a shutter valve which controls the fresh air inlet when the speed exceeds 160 km/h (100 miles/h).

Variable electronic blower control.

Air outlets in B pillars available for adjustment by rear seat passengers.

Changes in electrical connection and new connectors.

The interior temperature sensor is installed in the climate panel.

The exterior temperature sensor is installed in the right exterior rear view mirror (LH or RH drive does not matter).

Extended diagnostic functions available through the data link connector with VIDA.

New features of EEC controls

Separate, spring back buttons with indication diodes for

1. Selection of air distribution head/body/feet can be set to the desired combination.
2. Automatic climate control of temperature, air flow, air distribution recirculation, fresh air intake and air conditioning.
3. The defroster will automatically adjust the climate control to achieve the best possible window defrosting.
4. Electrically heated rear window.
5. Electrically heated front seats.
6. Recirculation.

Continuous knob with 7 indicated manual positions with indication diodes for blower control.

Selected functions are stored in memory and will remain there no matter how long the power to the CCM has been cut off.

Note. The automatic climate control or defroster requires the ignition key to be in position II, and this will reset any selected settings. (Recirculation can be manually controlled during automatic climate control, and the blower can be manually controlled during defrosting.) When the automatic climate control or defroster is turned off, the system will return to any selected settings.

New features of MCC/STD controls

Separate, spring back buttons with indication diodes for

1. Electrically heated rear window.
2. Electrically heated front seats.
3. Recirculation.

A 30 step knob for blower control.

The temperature controls regulate the temperature shutter valves through stepping motors.

The air distribution controls regulate the distribution shutter valves through a stepping motor.

Selected functions are stored in memory and will remain there no matter how long the power to the CCM has been cut off.

New features of cooler

There is a new drainage pipe which guides the water away from the blower motor casing and the filter housing.

The evaporator surface has a new treatment and a polyurethane sheath to reduce corrosion and bad smells.

The compressor has a higher capacity and is installed directly on the auxiliary unit bracket.

The compressor is started in a new fashion to avoid opening the safety valve.

TEV supplies a more even temperature regulation by adapting the amount of coolant to any requirements.

The freeze protection temperature sensor measures the temperature of the air that goes by the evaporator.

Linear pressure sensor installed directly on wiper.

Blower delay as customer setting. The delay is activated when complaints of bad smells occur, to remove any condensation water from the evaporator.

Service valves on both low and high pressure side.

Note. Coolant may only be filled from the high pressure side to avoid liquid coolant getting into the compressor.

Scheme 352

Output signals ECC/MCC/STD

Certain components are directly connected to the Climate control module and others are connected to other control modules in the network. The Electronic climate control (ECC) and Manual climate control (MCC) output signals differ only in that the ECC has one shutter motor more. Standard (STD) has the same signals as the Manual climate control (MCC) except for those signals controlling the compressor. The following output signals are sent from the Climate control module regardless of the type of climate control system

Blower fan speed via the power unit with the following functions

1. Stepless fan setting from zero to maximum voltage.
2. In case of short-circuit, locked blower fan motor, temperature too high or U < 9 V the power unit protects the blower fan motor by switching it off.

Recirculation and fresh air shutters opening.

Left side temperature switch control.

Right side temperature switch control.

Ventilation and floor shutter control. (On the Manual climate control(MCC)/Standard (STD) the motor also controls the defroster shutter.

Information to the combined instrument panel display via Driver information module (DIM).

Signals to VIDA via data link connector (DLC).

Output signals ECC/MCC

In addition to the common input signals the following signals are sent from the Climate control module when the system is an ECC or MCC

The Climate control module supplies the engine control module (ECM) with the following information (via the CEM)

1. If the air conditioning (A/C) compressor should operate.
2. If the idling speed should be normal or increased.

Output signals ECC

The following signals are specific for the Electronic climate control (ECC) climate control system

1. Defroster shutter opening control (ECC).

Air Conditioning Compressor control (ECC/MCC)

The Climate control module requests compressor activation with an air conditioning selected signal which is sent to the engine control module (ECM). Based on this signal, the signal from the engine coolant temperature, throttle position and the signal from the evaporator temperature sensor the engine control module (ECM) determines when the compressor should work.

The advantage with allowing the engine control module (ECM) to control the Air Conditioning Compressor is that it can delay the compressor switching on slightly, if the idling speed needs to compensate for the extra load for example.

See Design

Downloading software and replacing the control module

See Downloading software and replacing the control module

See Function

See Downloading software and replacing the control module

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Adding accessories and replacing the control module

See Adding accessories and replacing the control module

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Information

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