GF83.40-D-4015H Tempmatic (TM) Control and Operating Unit, Component Description

GF83.40-D-4015H Tempmatic (TM) Control And Operating Unit, Component Description

- with CODE (HH9) "Tempmatic" regulated air conditioning

On vehicles with code (HH9) Regulated air conditioning (Tempmatic), the engine residual heat utilization function can be used via the circulation pump (M13/4) up to August 31, 2008.
As of September 1, 2008, this is only possible if one of the following special equipment packages is also installed:
- Code (HZ5) 10 kW auxiliary water heater with timer
- Code (HZ9) Heater booster, diesel
- Code (H12) Auxiliary heater (warm water)
- Code (H13) Additional heat exchanger in cargo area







Location

Shown with code (H13) Additional heat exchanger in load compartment, with code (HH7) Additional air conditioning in rear or with code (H08) High-performance air conditioning
S98 AAC [KLA] control and operating unit

The comfort AAC control and operating unit is located in the center of the dashboard.

Task
The KLA control and operating unit is used to control the heater, air conditioning, ventilation and the residual engine heat utilization system (MRA) in the vehicle.
For vehicles with code (H13) Additional heat exchanger in load compartment, the rear heater is switched on and off and regulated over discrete lines.
For vehicles with code (HH7) Additional air conditioning in rear, the rear automatic air conditioning system is switched on and off and regulated over discrete lines.
For vehicles with code (H08) High-performance air conditioning, a more powerful rear automatic air conditioning system is switched on and off and regulated over discrete lines.

The AAC [KLA] control and operating unit communicates via the Controller Area Network bus Class B (interior) (CAN-B) with the following control units:
- With the EIS [EZS] control unit (N73)
- The KLA control and operating unit transmits, e.g. "GEBL_EIN (Blower motor (M2) activated)"
- The KLA control and operating unit receives, e.g. "KOMP_BAUS (Switch off refrigerant compressor (A9), acceleration)"

- With the instrument cluster (A1)
- The KLA control and operating unit transmits, e.g. "AC_OFF (Air conditioning off)"
- The KLA control and operating unit receives, e.g. "KL_58D_B (Instrument illumination brightness)"

- With the SAM control unit (N10)
- The KLA control and operating unit receives, e.g. "HHS_AN (Left heated rear window (R1/1) (HHS) and right heated rear window (R1/2) are switched on)"

- With the DBE control unit (N70) with code (LD0) Dome lamp with reading lights for driver/front passenger
- The KLA control and operating unit transmits, e.g. "REST_AKT (Residual heat utilization active)"
- The KLA control and operating unit receives, e.g. "RE_SYNC1 (Synchronization of rain/light sensor (B38/2)), Wischer_EIN_1 (Wiper request, stage 1)"

- With the warm water auxiliary heater control unit (N33/3), with code (H12) Auxiliary heater (warm water) or with code (HZ5) 10 kW auxiliary water heater with timer
- The KLA control and operating unit transmits, e.g. "STH_STUFE (Specified stage for stationary heater (STH))"
- The KLA control and operating unit receives, e.g. "GEBL�SE_EIN (Switch on blower motor)"

- With the electric PTC heater booster (N33/4) with code (HH2) Electric warm air auxiliary heater
- The KLA control and operating unit transmits, e.g. "PTC_STUFE (Specified stage for PTC heater booster)"
- The KLA control and operating unit receives, e.g. "PTC_LEISTUNG (PTC heater booster output)"

- With the 2nd warm water auxiliary heater control unit (N33/2), with code (HZ9) Heater booster, diesel or with code (HZ5) 10 kW auxiliary water heater with timer
- The KLA control and operating unit transmits, e.g. "ZUH_STUFE (Specified stage for heater booster (ZUH))"
- The KLA control and operating unit receives, e.g. "ZHZ_EIN (ZUH switched on)"

- With the PSM control unit (N26/15) with code (ED5) Parameterizable special module (PSM)
- The KLA control and operating unit transmits, e.g. "KOMP_EIN (Refrigerant compressor switched on)"

The KLA control and operating unit additionally reads in the following components:
- Refrigerant compressor control valve (A9y1)
- Evaporator temperature sensor (B10/6)
- Refrigerant pressure sensor (B12)
- Fresh air and air recirculation flap actuator motor (M16/21)
- Air distribution actuator motor (M16/22)
- Blend air flap actuator motor (M16/8)
- Interior temperature sensor (S98b1)
- Rear heater water valve potentiometer (A32/1r1), with code (H13) Additional heat exchanger in cargo area
- Evaporator temperature sensor (A32/2b1), with code (HH7) Additional air conditioning in rear
- Blend air flap potentiometer (A32/2r2), with code (HH7) Additional air conditioning in rear
- Refrigerant shutoff valve (A32/2y1) with integrated rear expansion valve, with code (HH7) Additional air conditioning in rear
- Roof refrigerant pressure sensor (B12/6), with code (H08) High-performance air conditioning
- Evaporator temperature sensor (A32/3b1), with code (H08) High-performance air conditioning
- Blend air flap potentiometer (A32/3r2), with code (H08) High- performance air conditioning

Temperature selection switch (S98s14)
The temperature selection switch can be used to set the temperature in the vehicle interior to between 15 and 29 �C as required. When the temperature selector switch is turned to the left, the air outlet temperature at the nozzles is reduced, turning to the right increases it. In the "MAX cooling" position (the temperature selection switch is turned all the way to the left in the detent position) and in the "MAX heating" position (the temperature selection switch is turned all the way to the right in the detent position), no more regulation takes place. Maximum cooling or maximum heating is performed.
The blend air flap actuator motor electronically adjusts the position of the blend air flap and shutoff flap for the front heater heat exchanger and regulates the refrigerant compressor over the refrigerant compressor control valve to match the set specified temperature.

Blower control button (+) (S98s10) and blower control button (-) (S98s11)
With the blower control button (+) and the blower control button (-), the blower output of the blower motor can be set to the following 5 stages via the blower regulator (M2n1):
- Stage 0
- Stage 1
- Stage 2
- Stage 3
- Stage 4

Blower output can be increased by pressing the blower control button (+). Blower output can be reduced by pressing the blower control button (-). Pressing and holding the blower control button (+) or blower control button (-) increases or reduces blower output quickly.
The current blower output is indicated by 4 red light emitting diodes (LED) at the right next to the blower control button (+) and the blower control button (-).

Air recirculation mode button (S98s6)
The air recirculation mode button can be used to switch the fresh air or air recirculation mode on and off. In fresh-air mode, ambient air is drawn into the front AC housing over the air inlet above the engine hood, the particulate filter and the fresh air and air recirculation flap.
In air recirculation mode, recirculated air is drawn from the vehicle interior into the front AC housing. In this case, the air is circulated in the vehicle and no fresh air is sucked in. After a period of 10 to 30 min (depending on outside temperature), the system automatically switches back to fresh air mode. The fresh air and air recirculation flap is adjusted by the fresh air/air recirculation flap actuator motor.
When the air recirculation mode is activated, the red LED in the air recirculation mode button lights up. When the fresh air mode is switched on, the red LED in the air recirculation mode button extinguishes.

AC OFF and residual heat system button (S98s4)
With status "terminal 61 ON" (engine running), actuation of the AC OFF and residual heat system button will switch the refrigerant compressor on or off (economy mode) over the refrigerant compressor control valve. If the refrigerant compressor is switched off, the red LED in the AC OFF and residual heat system button lights up.
With status "terminal 61 OFF" (engine stopped) and "terminal 15 OFF" (ignition off), the MRA is switched on by pressing the AC OFF and residual heat system button. The circulation pump and the 1st stage of the blower motor are activated. When the MRA is active, the red LED in the AC OFF and residual heat system button lights up.

Air distribution switch (S98s8)
The air distribution switch is used to electrically adjust the air distribution flaps over the air distribution actuator motor. The following positions are possible: defroster vents (12 o'clock position), defroster vents and footwell vents (3 o'clock position), footwell vents (6 o'clock position), dash support vents (9 o'clock position) as well as intermediate positions.

In-car temperature sensor
The interior temperature sensor measures the current interior temperature in the cab and forwards this as a signal over a discrete line to the KLA control and operating unit.

Reheat/defrost mode button (S98s5)
The reheat/defrost mode button is used to prevent the windows from fogging up by withdrawing humidity from the fresh or recirculated air using maximum cooling. Next, the fresh or recirculated air is heated by heating the air to the set temperature.
The refrigerant compressor is actuated and regulated over the refrigerant compressor control valve, and the blend air and shutoff flap over the blend air flap actuator motor.
When the reheat mode is active, the red LED in the reheat/defrost mode button lights up.

Rear air conditioning button (S98s7), with code (H13) Additional heat exchanger in load compartment, with code (HH7) Additional air conditioning in rear or with code (H08) High-performance air conditioning
For vehicles with code (H13) Additional heat exchanger in load compartment, the rear heater is switched on and off using the rear air conditioning button.
For vehicles with code (HH7) Additional air conditioning in rear, the rear automatic air conditioning is switched on and off using the rear air conditioning button.
For vehicles with code (H08) High-performance air conditioning, a more powerful rear automatic air conditioning is switched on and off using the rear air conditioning button.
The rate of air flow and the temperature of the rear heater, of the rear automatic air conditioning or of the more powerful rear automatic air conditioning are regulated via the rear blower control button (+) (S98s2) and the rear blower control button (-) (S98s3) as well as via the rear temperature selection switch (S98s15)

When the rear heater, rear automatic air conditioning or the more powerful rear automatic air conditioning is switched on, the red LED in the rear air conditioning button lights up.

Rear blower control button (+) and rear blower control button (-), with code (H13) Additional heat exchanger in load compartment, with code (HH7) Additional air conditioning in rear or with code (H08) High-performance air conditioning
The rear blower control button (+) and rear blower control button (-) are used to regulate the output of the following blower motors using the relevant control:
- Rear heater blower motor (A32/1m1) via rear heater blower regulator (A32/1a1), with code (H13) Additional heat exchanger in cargo area
- Blower motor (A32/2m1) via blower regulator (A32/2a1), with code (HH7) Additional air conditioning in rear
- Blower motor (A32/3m1) via blower regulator (A32/3a1), with code (H08) High-performance air conditioning

The output of the listed blower motors is adjusted in the following 3 stages:
- Stage 1
- Stage 2
- Stage 3

Blower output can be increased by pressing the rear blower control button (+). Blower output can be reduced by pressing the rear blower control button (-). Pressing and holding the rear blower control button (+) or rear blower control button (-) increases or reduces blower output quickly.
The current blower output is indicated by 3 red LED at the left next to the rear blower control button (+) and the rear blower control button (-).

Rear temperature selection switch, with code (H13) Additional heat exchanger in load compartment, with code (HH7) Additional air conditioning in rear or with code (H08) High-performance air conditioning
For vehicles with code (H13) Additional heat exchanger in cargo area, the rear temperature selection switch is used to regulate the flow of coolant through the rear heater water valve (A32/1y1) to the rear heater heat exchanger. When the rear temperature selector switch is turned to the left, the flow rate is reduced, turning to the right increases it.
To regulate the coolant flow and in order to detect the position of the rear heater water valve, the KLA control and operating unit reads in the rear heater water valve potentiometer over a discrete line.
For vehicles with code (HH7) Additional air conditioning in rear, the rear temperature selection switch is used to regulate the rate of air flow over the rear evaporator by adjusting the rear blend air flap with the blend air flap actuator motor (A32/2m2). In addition, the refrigerant shutoff valve is opened with the integrated rear expansion valve. When the rear temperature selection switch is turned to the left, the rate of air flow is increased, turning to the right decreases it.
To regulate the rate of air flow and in order to detect the position of the blend air flap actuator motor, the KLA control and operating unit reads in the blend air flap potentiometer over a discrete line.

For vehicles with code (H08) High-performance air conditioning, the rear temperature selection switch is used to regulate the rate of air flow over the rear evaporator by adjusting the rear blend air flap with the blend air flap actuator motor (A32/3m2). In addition, the refrigerant shutoff valve is opened with the integrated rear expansion valve. In addition, the 2nd refrigerant compressor (A9/7) and thereby the flow of refrigerant are regulated through the rear evaporator via the 2nd refrigerant compressor magnetic clutch (A9/7y1).

When the rear temperature selection switch is turned to the left, the rate of air flow is increased, by turning it to the right it is reduced.
To regulate the rate of air flow and in order to detect the position of the blend air flap actuator motor, the KLA control and operating unit reads in the blend air flap potentiometer over a discrete line.







Design

Shown with code (H13) Additional heat exchanger in load compartment, with code (HH7) Additional air conditioning in rear or with code (H08) High-performance air conditioning
S98 AAC [KLA] control and operating unit
S98b1 In-car temperature sensor
S98s2 Rear blower control button (+)
S98s3 Rear blower control button (-)
S98s4 AC OFF and residual heat system button
S98s5 Reheat/defrost mode button
S98s6 Air recirculation mode button
S98s7 Rear air conditioning button
S98s8 Air distribution switch
S98s10 Blower control button (+)
S98s11 Blower control button (-)
S98s14 Temperature selection switch
S98s15 Rear temperature selection switch