Climate Control Module (CCM)

System Overview

Control Module







The climate control module controls the climate control system and the buttons in the dashboard environment panel.

The climate control module is located in the center console. There are three versions of control module (market dependent). These are:
- Electronic Climate Control. This fully automatic climate control system has air conditioning and the option of manual settings
- Manual Climate Control. A manual climate control system with air conditioning
- Standard Heater. A manual climate control system without air conditioning.

The climate control module (for the electronic climate control and manual climate control) obtains the current passenger compartment temperature from a sensor integrated into the control module.

The intensity of the dashboard lighting is regulated based on a signal from the twilight sensor. The twilight sensor is located at the front of the dashboard environment panel under the button for air distribution to the floor.

The climate control module communicates with components which are directly connected and with other control modules and also with components via serial communication and Control area network (CAN).

The control module checks input and output signals and carried out activations via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects an error. In certain cases the control module replaces the faulty signal with a substitute value.

Diagnostic trouble codes (DTC) are stored in the control module memory. This information can be read off using the diagnostic tool via the data link connector (DLC) in the car.

A simple method for checking that the climate control module has a power supply and is grounded is to increase or decrease the blower fan speed. Another method is to activate one of the functions controlled by the buttons on the dashboard environment panel.

Signals










The table below summarizes input and output signals to and from the climate control module. The signal types are divided into directly connected signals, serial communication and Controller area network (CAN) communication. The illustration below displays the same information with the Volvo component designations.

Design

Climate Control Unit







The Climate Control Unit consists of the following components:

1. Heater element
2. Damper motor, temperature, left
3. Blower fan
4. Damper motor, fresh air/recirculation
5. Power unit for blower fan motor
6. Particle filter
7. Damper motor, ventilation and floor (also defroster for MCC/STD)
8. Damper motor, temperature, right
9. Damper motor defroster (ECC).

Engine coolant constantly flows through the heater element. There is no valve to regulate the flow. The selected temperature is achieved using dampers for the right and left-hand sides of the car installed upstream and downstream of the heater element. These control the amount of air to be warmed. There are also dampers downstream of the heater element that guide the airflow to the correct air vent.

The climate control module provides infinitely variable electronic blower fan control. When AUTO mode (only electronic climate control) is engaged the climate control module (CCM) adapts the blower fan speed to the setting of the controls and the vehicle speed. The blower fan can be set to run-on in order to reduce residual moisture in the evaporator.

A timer located in the central electronic module (CEM) controls the run-on time. 50 minutes after the engine has been switched off and the ignition has been turned to position 0 or I the central electronic module (CEM) supplies power to the climate control module (CCM) and the blower fan is activated at full speed for 7 minutes. This run-on dries the evaporator and prevents bad odors.

This function is programmed at the factory, but can be deactivated in the event of customer complaints via programming of customer parameters. Programming is carried out via VADIS.

The function is only available to cars of structure week 199850 and later.

All damper motors are of the stepper type. Their position and speed is controlled electronically.

Manual climate control and standard climate control have four stepper motors controlling the following dampers:
- Ventilation/floor/defroster via a link system
- Recirculation and fresh air via a link system
- Temperature left
- Temperature right.

For electronic climate control (ECC) there is an extra stepper motor which controls the defroster. The wiring between the damper motors and the climate control module (CCM) consists of four cables for supply voltage and directional control and a separate cable for each motor which controls the motor to be activated. Each motor has four coils. The corresponding coils in each motor are supplied with power at the same time. The motors are only supplied with power if they are grounded at the same time. When a new position is selected for the damper motor, the climate control module (CCM) calculates how many steps are required to complete the movement. The climate control module (CCM) then activates the damper motor with the necessary number of steps. When the motor is instructed to move to an end position, the motor is activated until it stops. This end position is then used as a limit position. This means that the damper motors are self-adjusting, but only after the limit positions have been reached. When replacing the damper motors, ensure that the self-adjustment is carried out. Otherwise the customer may experience defective climate control.

There are diagnostics for the blower fan and damper motors.

Air conditioning (ECC and MCC only)







The engine control module (ECM) controls the A/C compressor. When the A/C switch on the dashboard environment panel is activated, a request to activate the compressor is transmitted via Control area network (CAN) to the engine control module (ECM). The engine control module (ECM) determines when the compressor must operate.

If any of the following conditions are met the compressor is disconnected:
- High engine coolant temperature (ECT)
- Wide open throttle (WOT)
- The engine has just been started
- Overpressure in the air conditioning (A/C) system.

When the engine is started the engine control module (ECM) activates the air conditioning compressor for a short period even if the climate control module (CCM) has not transmitted a request about this. This is carried out for diagnosis. This check is carried out at all temperatures exceeding -6°C.

The advantage in allowing the engine control module (ECM) to control the air conditioning compressor is that it can delay compressor activation somewhat, if the idling speed must be compensated for the extra load for example.

Sun sensor (electronic climate control only)







The sun sensor transmits information about sun intensity to the climate control module (CCM).

The sun sensor consists of a photo diode which is supplied with power from the control module. The conductivity of the diode depends on the amount of light to which it is exposed. The diode is located under a diffusing lens which reduces the sensitivity of the photo diode to the angle of the light hitting it. Increased sun intensity reduces the voltage over the photo diode. The control module measures the voltage over the photo diode and compensates for high sun intensity by lowering the ventilation air temperature, changing the distribution of air and increasing the speed of the blower fan.

The climate control module (CCM) starts to compensate the blower fan speed at a sun intensity of 400 W/sq.m and reaches maximum compensation at a sun intensity of 1000 W/sq.m.

The sun sensor is located in the middle of the dashboard by the windshield.

There are diagnostics for the sun sensor.

Air quality sensor (electronic climate control only, option)







The air quality sensor is available as an option for the electronic climate control from model year 2000. Its function is to transmit a signal to the climate control module (CCM) if it detects increased concentrations of pollutants in the outside air.

The air quality sensor measures the COx and NO x content.

The air quality sensor compares current values with previous ones and can calculate changes in pollutant concentrations.

The signal from the air quality sensor to the climate control module (CCM) is a pulse width modulation (PWM) signal and has four stages, 0-3:

- signal 0= no increase in or reduced pollutant level
- signal 1=gradual increase in pollutant level
- signal 2=moderate increase in pollutant level
- signal 3=rapid increase in pollutant level.

The control module uses the signal to control the recirculation damper motor.

The air quality sensor is located on the right-hand side of the fresh air intake under the cowl.

There are diagnostics for the air quality sensor.

Switches, dashboard environment panel, (lower section)







Across the lower section of the dashboard environment panel there is a 12V socket and space for a maximum of seven switches.

Each switch has its own identity. This is unique for the relevant function. The switches can therefore be positioned in any location on the dashboard environment panel, as long as they are installed in the off position. They do not have to be in any particular order. However, the identity of the installed switches must correspond with the car configuration file so that they can be activated.

There are diagnostics for the switches.

Function

Controlling the climate in the passenger compartment







The way in which the climate in the passenger compartment is regulated depends on the type of climate control module (CCM) in the car.

Electronic climate control
Electronic climate control means that either manual settings or the AUTO function can be used. In the latter case the control module automatically regulates heat, air conditioning, recirculation and air distribution until the selected temperature is achieved.

Manual climate control
Manual climate control means that heat, air conditioning, recirculation and air distribution must be selected manually.

STD
STD means that heat, recirculation and air distribution must be selected manually.

The climate control module (CCM) (3/112) regulates the following:
- Activation of the air conditioning (A/C) compressor (8/3) with a request via the Controller area network (CAN) to the engine control module (ECM) (4/46)
- Controlling the damper motors. For electronic climate control (6/48), (6/95), (6/96), (6/102) and (6/103). For manual climate control; (6/48), (6/69), (6/95) and (6/96)
- Blower fan speed (6/28).

The climate control module (CCM) regulates the climate in the passenger compartment based on the following input signals:
- The passenger compartment temperature, signal from the internal passenger compartment temperature sensor
- The outside temperature, signal from the outside temperature sensor (7/11)
- The evaporator temperature, signal from the evaporator temperature sensor (7/41)
- Sun roof status. Signal from the sun roof control module (4/33) via the upper electronic module (UEM) (4/70) over the Controller area network (CAN)
- Side window status. Signals from the driver door module (DDM) (3/126) and passenger door module (PDM) (3/127) via the Controller area network (CAN)
- Door status. Signal from the central electronic module (CEM) (4/56) via the Controller area network (CAN)
- Sun intensity. Signal from the sun sensor (7/12)
- Speed. Signal from the brake control module (BCM) (4/16) (previously ABS), via the Controller area network (CAN)
- Windshield wiper status. Signal from the steering wheel module (SWM) (3/130) via the Controller area network (CAN).

The climate control module (CCM) (for electronic climate control) uses information about the status of the sun roof, side windows and doors to determine how it should compensate for changes in the passenger compartment temperature. If side windows, doors or the sun roof are opened, the climate control module (CCM) will not compensate for a change in passenger compartment temperature. Instead it maintains the same level of climate control for the compressor and blower fan as before. The climate control module (CCM) (for electronic climate control) uses the signal from the steering wheel module (SWM) to establish whether the windshield wipers are switched on. This is to regulate the blower fan and the damper motor to remove any mist from the inside of the windshield when it rains.

The climate control module (CCM) (for electronic climate control) uses the signal from the sun sensor to compensate for high sun intensity by decreasing the temperature of ventilation air, changing air distribution and increasing the speed of the blower fan.

The climate control module (CCM) (for electronic climate control and manual climate control) uses the signal from the evaporator temperature sensor to control the activation of the air conditioning (A/C) compressor. If the signal from the evaporator temperature sensor indicates an evaporator temperature below 6°C, the compressor cannot be activated because of the risk of freezing.

To maintain a constant flow of air in the passenger compartment the climate control module (CCM) (for electronic climate control) uses the speed signal from the brake control module (BCM) to regulate the speed of the blower fan. Generally, as the speed of the car increases the speed of the blower fan decreases.

At higher speeds the flow of air into the fresh air damper is adjusted.

Seat heaters







The seat heaters are activated by pressing the switches on the climate control module (CCM) (3/112). The climate control module (CCM) transmits information via the Controller area network (CAN) about the status selected for each seat to the central electronic module (CEM) (4/56). The central electronic module (CEM) then transmits the information to the relevant control module for seat heating (4/201, 4/202). The control modules for the seat heaters then control the current to the heater pad for the left-hand seat (9/16, 9/18) and right-hand seat (9/17, 9/19).

The central electronic module (CEM) also transmits information to the climate control module (CCM) about whether the seat heaters are activated or not. The climate control module (CCM) uses this information to light/turn off the LEDs on the buttons.

Recirculation control (electronic climate control only)







The climate control module (CCM) (3/112) controls the recirculation during the following conditions for electronic climate control:
- The recirculation switch is on (the LED lights orange)
- The system is in AUTO position and there is a large difference between the desired and current temperature
- The car is equipped with an air quality sensor, and the recirculation switch is on (the LED light green).

The air quality sensor transmits a signal to the climate control module (CCM) if it detects high concentrations of pollutants in the outside air. When this occurs the climate control module (CCM) transmits a signal to the damper motor for recirculation (6/48) to close the fresh air damper and to use recirculated air. The level of recirculation is controlled by the signal from the air quality sensor:
- signal 1 provides partial recirculation for speeds below 85 km/h, no recirculation for speeds exceeding 85 km/h
- signals 2 and 3 provide 100% recirculation.

If the high level of pollutants remains the system stays in recirculation for a certain time, maximum of 10 minutes. The time that the system is recirculating is determined by the outside temperature, if the air conditioning (A/C) is on and if the windshield wipers are activated. The system returns to fresh air for a short time before recirculation is resumed. The particle filter absorbs most of the pollutants entering the passenger compartment during this time. The maximum time prevents misting and musty air.

The air quality transmits information about the content of pollutants to the climate control module (CCM). This information is graded into four levels, and the information used for diagnosis.

Recirculation is never permitted if the defroster is selected. The climate control module (CCM) requests the compressor when the evaporator temperature exceeds 3°C.

Heated rear windshield and door mirrors







The heated rear windshield and door mirrors are activated by pressing the switch on the climate control module (CCM) (3/112). The climate control module (CCM) transmits information to the central electronic module (CEM) (4/56) about the selected heating status. The central electronic module (CEM) transmits a signal to the driver's door module (3/126) and passenger door module (PDM) (3/127) for the heated door mirrors and to the rear electronic module (REM) (4/58) for the heated rear windshield.

The central electronic module (CEM) also transmits information to the climate control module (CCM) about whether the seat heaters are activated or not. The climate control module (CCM) uses this information to light/turn off the LED on the button.

Switch functions, dashboard environment panel, (lower section)
The following functions can be activated using the switches on the dashboard environment panel:
- Folding door mirrors (market dependent)
- Bi-fuel, on/off (market dependent)
- Valet lock, on/off
- Child lock, on/off (market dependent)
- STC, off/on (option)
- DSTC, off/on (option)
- Auxiliary lamps, off/on (option)
- Reduced alarm, on/off (option).

In order for certain functions to be activated the engine must be switched on and/or the master key must be in position II.

Folding door mirrors
When the switch for the folding door mirrors is activated, information is transmitted by the climate control module (CCM) to the driver's door module (3/126) and the passenger door module (PDM) (3/127) via the Controller area network (CAN).

Bi-fuel
When the bi-fuel switch is activated, a signal is transmitted from the climate control module (CCM) to the engine control module (ECM) (4/46) on the Controller area network (CAN) via the central electronic module (CEM). The engine control module (ECM) transmits a signal to the climate control module (CCM) about the type of fuel being used. The climate control module (CCM) uses this signal to light/turn off the LED on the switch.

HINT: This section will first be accessible during 2003.

Valet lock/child-proof lock
When activating the valet lock switch or the child lock switch information is transmitted to the rear electronic module (REM) via the Controller area network (CAN).

STC or DSTC
When the STC or DSTC switch is activated, a signal is transmitted from the climate control module (CCM) to the brake control module (BCM) (previously ABS) (4/16) via the Controller area network (CAN). The brake control module (BCM) transmits a signal to the climate control module (CCM) about whether the STC or DSTC functions are operating. The climate control module (CCM) uses this signal to light/turn off the LED on the switch.

Auxiliary lamps
When the auxiliary lamps switch is activated, information is transmitted from the climate control module (CCM) to the central electronic module (CEM). The central electronic module (CEM) transmits a signal to the climate control module (CCM) about whether the auxiliary lamps are on or not. The climate control module (CCM) uses this information to light/turn off the LED on the switch

Reduced alarm
When activating the reduced alarm switch information is transmitted via the Controller area network (CAN) to the upper electronic module (UEM) and rear electronic module (REM).

Rear A/C
When activating the switch for rear A/C information is transmitted via the Controller area network (CAN) to the rear electronic module (REM). From this signal and the signal from the engine control module (ECM) indicating whether the engine is running or not, the rear electronic module (REM) will activate/deactivate the relay supply to the rear A/C system. The rear electronic module (REM) transmits a signal indicating whether the rear A/C is on or not to the climate control module (CCM) via the control area network (CAN). The climate control module (CCM) uses this information to light/turn off the LED in the switch.

Diagnostic Functions

General
The climate control module has a built-in diagnostic system which continuously monitors internal functions and input and output signals.

Diagnostic trouble codes (DTCs)
Diagnostic trouble codes (DTCs) are stored in the control module if the climate control module detects a fault. Every diagnostic trouble code (DTC) has a counter which records the number of cycles which have been fault-free since the diagnostic trouble code (DTC) was stored (intermittent fault). A fault which is detected in each operating cycle is defined as permanent. A fault which is detected in one or more (but not all) operating cycles is defined as intermittent.

An operating cycle is the period from when the ignition was switched on, remained on for at least 10 seconds and was finally switched off for at least 10 seconds.

Reading and erasing diagnostic trouble codes (DTCs)
Stored diagnostic trouble codes (DTCs) can be read off and erased using this function.

Reading off input and output signals
Using this function, the status or value of parameters can be read off. The presentation of the status or value can be obtained graphically or digitally.

Reading off extended fault-tracing information, climate control module
This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

Description of programmable parameters, customer adaptation
Certain parameters of the climate control module can be read off and programmed using this function. The purpose of this programming is:
- to read the programmed parameters before replacing the control module. This is so the same parameters can be entered into the new control module
- to adapt the function of the control module for the equipment levels of the car (passenger compartment ventilation filter, parking heater)
- to adapt the function of the control module to the requirements of the driver.

Passenger compartment ventilation filter compensation, status
Indicates the status for the activation of passenger compartment ventilation filter compensation.
OFF = Compensation not active
ON = Compensation active (preset)

Blower fan run-on, status
Provides the status for activation of the blower fan run-on. The run-on dries the evaporator and prevents bad odors which may otherwise result from residual moisture in the system.
OFF = Run-on inactive
ON = Run-on active (preset)

Blower fan speed, value
Allows the speed to be modified for the blower fan when the climate control system is in AUTO position. Modifying the parameters means that the climate control system either blows more or less air than the preprogrammed value, to correspond to the request of the driver.

Gives the voltage value for adaptation of the blower fan speed.
-1.0 - +1.0 V (0 V preset)

Setting for air distribution for the floor/defroster residual heat, value
Indicates the setting of the air distribution between the floor and defroster.

10/90 - 90/10% (70/30% preset)

Setting for air distribution for the floor/defroster parking heater, value
Indicates the setting of the air distribution between the floor and defroster.

10/90 - 90/10% (70/30% preset)

Description of component/function activation

Self-adjustment of damper motors
This function can be used to carry out self adjustment of the limit positions for the damper motors. Self adjustment must be carried out if, after checks, one or more of the damper motors do not reach their limit positions or the climate control module is replaced. There are a number of possible reasons for a damper motor not reaching its end positions. For example, the motor or the damper has been turned manually, the voltage supply may have been cut, or a component has been replaced.
Downloading Software And Replacing The Control Module
New software can be downloaded into the climate control module. When ordering software, the hardware and the software in the car is compared to the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.

The entire climate control module must be replaced as one unit. The exceptions are the fan for the passenger compartment temperature sensor and the switches on the lower section of the dashboard environment panel.

Five customer parameters can be programmed into the climate control module. These customer parameters are stored in the control module but not in the Volvo central database. This means that the customer parameters must be reprogrammed when the hardware is replaced.