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HEATING COMPONENTS
–Heater matrix:
The external air entering the heating and air conditioning device (HVAC) is heated by the heater matrix.
–Passenger Compartment Heating Resistors (depending on version):
The passenger compartment heating resistors are an electric heating system located in the passenger compartment
ventilation heating unit. This system acts as an additional heater which operates when the engine is cold (when
starting).
Passenger Compartment Heating Resistors (RCH)
●ACTUATORS
–Air distribution flap:
This flap enables the air flowing into the passenger compartment to be directed.
–Air mixing flap:
This flap enables the temperature requirements of the occupants to be met.
–Recirculation flap:
This flap prevents the entry of exterior air. In this case, the passenger compartment is isolated from the exterior and
air is blown in the passenger compartment in a closed circuit.
●OTHERS
–Passenger compartment blower unit:
The passenger compartment blower unit is controlled by the MVPR (Resistive Blower Dimmer Module).
HEATING
Fault finding - Role of components
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HEATING
Fault finding - Function61A
Summary diagram of components controlled or managed by the UCH:
Summary diagram of components controlled or managed by the injection computer:Rear screen de-icing and
rear-view mirror de-icer
(depending on version)External temperature sensor
(depending on version)
Actuator controlSensor management
UCH
Heated rear screen control
management
Relay No. 1 for the
Passenger
Compartment
Heating resistorsRelay No. 2 for
the Passenger
Compartment
Heating
resistorsEngine cooling
fan assemblyEngine coolant
temperature sensor
Actuator controlSensor
management
Engine injection computer
Management of the additional heater (heater resistor control) depending on the equipment
Key:
Wire connections =
Multiplex connections =
Vehicle
multiplex
network
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HEATING
Fault finding - Conformity check
SUB-FUNCTION: HEATING
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Test conditions: engine stopped, ignition on.
ComputerParameter or Status
checked or ActionDisplay and
notesFault finding
UCH (see 87B,
Passenger
compartment
connection unit)ET015:Passenger
compartment
blowerINACTIVE
(according to test conditions:
see Notes).In the event of a fault, refer to the
interpretation of this status.
Note: This status only operates for
manual air conditioning and
heating versions.
PR001: Battery voltage10.5 V < X < 14.4 VIf there is a fault, refer to the
interpretation of this parameter
If the fault is still present, carry out
fault finding on the charging circuit
(see MR 411 Mechanical, 16A,
Starting - charging circuit).
PR002: Exterior
temperature
(depending on
equipment)X = exterior temperature ± 5 °C
(invalid value: 215 °C)If there is a fault, refer to the
interpretation of this parameter
PR024: Engine coolant
temperatureX = engine coolant
temperature in ˚CIn the event of a fault, see the
interpretation of this parameter.
ET239: Ignition switch
position+ after ignition feedIn the event of a fault, refer to the
interpretation of this status.
PR025: Engine speed0 rpmIf there is a fault, refer to the
interpretation of this parameter
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HEATING
Fault finding - Conformity check61A
SUB-FUNCTION: HEATING (CONTINUED)
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application conditions: engine stopped, ignition on.
ComputerParameter or Status
checked or ActionDisplay and
notesFault finding
Injection
(see 13B, Diesel
injection or 17B,
Petrol injection)PR064: Coolant
temperatureX = engine coolant
temperatureIf there is a fault, refer to the
interpretation of this parameter
ET111: RCH number setNO
Note: Depending on the
requirements of the injection
system (power requirement,
torque reduction, etc.), the
injection computer sets the
controlled passenger
compartment heating resistor
stage number (no more,
no less)In the event of a fault, refer to the
interpretation of this status.
ET112: Passenger
compartment
heating resistor
cut-offYESIn the event of a fault, refer to the
interpretation of this status.
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HEATING
Fault finding - Conformity check61A
SUB-FUNCTION: USER SELECTION
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Test conditions: engine stopped, ignition on.
ComputerParameter or Status
checked or ActionDisplay and Notes Fault finding
UCH (see 87B,
Passenger
compartment
connection unit)ET028: Heated rear
screen buttonPRESSED if the heated
rear screen key on the air
conditioning control panel is
pressed.
RELEASED otherwise.In the event of a fault, refer to the
interpretation of this status.
Note: This status only operates for
manual air conditioning and heating
versions.
ET015: Passenger
compartment
blowerINACTIVE
(according to test
conditions: see Notes).In the event of a fault, refer to the
interpretation of this status.
Note: This status only operates for
manual air conditioning and heating
versions.
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HEATING
Fault finding - Conformity check61A
SUB-FUNCTION: HEATING
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application conditions: engine at idle speed, vehicle speed zero.
ComputerParameter or Status
checked or ActionDisplay and Notes Fault finding
UCH (continued)
(see 87B,
Passenger
compartment
connection unit)ET239: Ignition switch
position+ after ignition feedIn the event of a fault, refer to the
interpretation of this status.
PR025: Engine speed800 rpm ± 50 rpmIn the event of a fault, see the
interpretation of this parameter.
PR024: Engine coolant
temperatureX = engine coolant
temperatureIn the event of a fault, see the
interpretation of this parameter.
ET015: Passenger
compartment
blowerACTIVE
(according to test
conditions: see Notes).In the event of a fault, refer to the
interpretation of this status.
Note: This status only operates for
manual air conditioning and heating
versions.
PR001: Battery voltage12.5 V < X < 14.4 VIn the event of a fault, see the
interpretation of this parameter. If
the fault is still present, carry out fault
finding on the charging circuit
(see MR 411 Mechanical, 16A,
Starting - charging circuit).
PR002: Exterior
temperature
(depending on
equipment)X = exterior temperature:
5 ˚C (invalid value:
215 ˚C)In the event of a fault, see the
interpretation of this parameter.
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HEATING
Fault finding - Conformity check61A
SUB-FUNCTION: HEATING
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application conditions: engine at idle speed, vehicle speed zero.
ComputerParameter or Status
checked or ActionDisplay and
notesFault finding
Injection
(see 13B, Diesel
injection or 17B,
Petrol injection)PR064: Coolant
temperatureX = engine coolant
temperatureIn the event of a fault, see the
interpretation of this parameter.
ET111: RCH number
setYES or NO
Note: Depending on the
requirements of the injection
system (power requirement,
torque reduction, etc.), the
injection computer sets the
controlled passenger
compartment heating resistor
stage number (no more,
no less).In the event of a fault, refer to the
interpretation of this status.
ET112: RCH cut-offYES or NO
Note: Depending on the
requirements of the injection
system (power requirement,
torque reduction, etc.), the
injection computer sets the
controlled passenger
compartment heating resistor
stage number (no more,
no less).In the event of a fault, refer to the
interpretation of this status.
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HEATING
Fault finding - Conformity check61A
SUB-FUNCTION: USER SELECTION
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application conditions: engine at idle speed, vehicle speed zero.
ComputerParameter or Status
checked or ActionDisplay and
notesFault finding
UCH (see 87B,
Passenger
compartment
connection unit)ET028:Heated rear
screen buttonPRESSED if the heated rear
screen key on the air conditioning
control panel is pressed.
RELEASED otherwise.In the event of a fault, refer to the
interpretation of this status.
ET015:Passenger
compartment
blowerACTIVE
(according to test conditions:
see Notes).In the event of a fault, refer to the
interpretation of this status.