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CLIMATE CONTROL
Fault finding - List and location of components
List and location of components
System (cold loop, hot loop and components)
1Heating and air conditioning unit
2Heater matrix
3Expansion valve and evaporator
4Coolant circuit
5Cold loop
6Condenser and radiator
7Compressor
●COLD LOOP COMPONENTS
–Compressor: This is located at the bottom on the left-hand side, next to the radiator in the engine compartment.
–Condenser: This is located between the radiator and the cooling fan assembly.
–Dehydrator reservoir: This is located on the left-hand side of the condenser outlet.
–Heating and air conditioning unit: This is located under the dashboard.
–Thermostatic expansion valve: This is located to the left of the heating and air conditioning unit on the
bulkhead.
–Evaporator: This is located to the right of the thermostatic expansion valve in the heating and air conditioning
unit.
–High pressure pipe: This pipe connects the compressor, condenser, dehydrator reservoir, and expansion valve
inlet in series (it is located in the engine compartment on the left-hand side).
–Low pressure pipe: This pipe connects the expansion valve, buffering capacity, evaporator, and compressor
inlet in series (it is located in the engine compartment on the left-hand side).
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Fault finding - Role of components
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62B
–High and low pressure pipes: (see figure below)
●The High Pressure and Low Pressure pipes are composed of rigid aluminium pipes and flexible pipes that
enable engine-related movements to be absorbed.
●Two filler valves (High Pressure and Low Pressure) can be accessed in order to fill (or drain) the refrigerant loop.
●The connections must be checked in the event of a refrigerant fluid leak.
Cold loop pipes
1Buffering capacity
2Expansion valve outlet
3Expansion valve inlet
4High pressure filler valve
5Low pressure filler valve
6Condenser inlet
7Condenser outlet
8Pressure sensor
9Compressor inlet
10 Compressor outlet
●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 the equipment): (see figure below)
The passenger compartment heating resistors (RCH) are electrical heating devices in the air conditioning unit. This
system is an additional heating system which operates when the engine is cold (when starting).
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Fault finding - Role of components
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The passenger compartment blower unit is used to vary the rate at which air is blown into the passenger
compartment, depending on the requirements of the customer.
–Cooling fan assembly:
The cooling fan assembly motor is normally used in order to promote heat exchange in the condenser and therefore
improve the performance of the air conditioning system. Activation of the air conditioning fan unit depends, among
other things, on the vehicle speed and high pressure in the loop.
–Climate control computer:
The climate control computer is in permanent communication with the UCH and injection computers. It controls a
number of parameters:
●Meteorological (temperature, etc.)
●Vehicle (speed, engine speed, circuit temperature and pressure)
●Comfort (interior temperature).
Climate control panel: front panel
Climate control panel: rear panel
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CLIMATE CONTROL
Fault finding - Function
GENERAL INFORMATION:
The climate control function which is fitted to the new Twingo depends on the three computers: injection, UCH and
climate control (DISTRIBUTED FUNCTION).
Fault finding on the air conditioning is performed in two different ways using the diagnostic tool.
The first procedure consists of performing fault finding on each computer which allows dialogue to be established
with just one computer (select the climate control computer).
The second procedure consists of performing fault finding on each function which allows communication with all
three computers belonging to the CLIMATE CONTROL function.
DESCRIPTION OF THE OPERATION OF THE CLIMATE CONTROL COMPUTER:
The climate control computer controls the passenger compartment ventilation, the distribution motor, the mixing
motor and the recirculation motor.
The climate control computer also controls the interior temperature sensor.
The sensor and the three motors are connected to the climate control computer by wire connections. The climate
control computer controls the passenger compartment ventilation using a modulated control signal (square pulse
signal) sent to a power module (MVPE) by a wire connection.
All other signals used by the climate control computer or transmitted by this computer to other computers are sent on
the multiplex network.
The production of cold air (cold loop) and hot air (heating) is controlled by the other two computers involved in the
CLIMATE CONTROL function (UCH and engine injection computer).
Special notes on operation:
–When the engine is stopped, the passenger compartment fan rotates more slowly than when the engine is
running.
–If any of the actuators are faulty, the air conditioning can no longer control them, but the setting requests are still
displayed on the control panel: warning lights light up, display of symbols on the control panel (distribution motor
position, passenger compartment blower speed, AC symbol, etc.).
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Fault finding - Function62B
Vehicle
multiplex
network
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 control Sensor management
UCH
Air conditioning request
managementHeated rear screen control
management
Relay No. 1 for
the Passenger
Compartment
Heating
ResistorsRelay No. 2 for
the Passenger
Compartment
Heating
ResistorsAir conditioning
compressorEngine cooling
fan assemblyEngine
coolant
temperature
sensorRefrigerant
fluid
pressure
sensor
Actuator control Sensor management
Engine injection computer
Management of the cold loop (refrigerant pressure,
engine cooling fan activation request,
compressor activation authorisation, etc.)
Key:
Wire connections =
Multiplex connections =
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CLIMATE CONTROL
Fault finding - Replacement of components
REPLACING THE CLIMATE CONTROL COMPUTER
–Note the computer configuration according to the optional equipment fitted on the vehicle (see climate control
computer configuration) or using the Shared World Information (ICM).
–Ensure that the ignition is switched off.
–After approval from the Techline, replace the computer.
–Switch on the ignition and carry out a check using the diagnostic tool.
–Configure the computer according to the vehicle specifications.
–Switch off the ignition and then back on for the configurations to register.
–Check in the Read configuration menu that the configurations have been recognised correctly.
–Check for faults and apply the corresponding fault finding procedure for any faults shown on the diagnostic tool.
–Clear any stored faults.
–Run command VP001 Enter VIN.
–Start the engine, switch on the air conditioning and ensure that it is operating correctly. WARNING
Before replacing the climate control computer, check that it is faulty (read faults, conformity of variables,
read customer complaints). Replacement of the computer must be authorised by the Techline after a fault
finding log has been completed and submitted.
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CLIMATE CONTROL
Fault finding - Interpretation of faults
DF001
PRESENT
OR
STOREDCOMPUTER
1. DEF: Internal electronic fault
NOTESConditions for running fault finding on a present or stored fault:
Apply this fault finding procedure if the fault reappears as present or stored after the
ignition is switched of f and on again.
Switch off the ignition and wait for the immobiliser warning light (Power-latch) to come one,
–Switch on the ignition again.
–Start the engine and switch on the air conditioning.
If the fault recurs, contact the Techline.
If the fault does not reappear: leave the climate control switched on and select various ventilation and air
distribution settings to check that the system is operating correctly.
–Check that no fault is displayed.
If the fault is still present, contact the Techline.
AFTER REPAIRFollow the instructions to confirm repair.
If the computer was replaced (at the request of the Techline), reconfigure the
computer (see Configurations and programming).
Deal with any other faults.
CLIM_V44_DF001
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Fault finding - Interpretation of faults
Vdiag No.: 44
62B
DF007
PRESENT
OR
STOREDINTERIOR TEMPERATURE SENSOR CIRCUIT
CC.0 : Short circuit to earth
CO.1 : Short circuit or open circuit to + 12 V
NOTESConditions for running fault finding on a present or stored fault:
Apply this fault finding procedure if the fault reappears as present or stored after the
ignition is switched on and air conditioning activation is requested with the engine
running.
Special notes:
The interior temperature sensor is located at the top of the roof in the unit under the
rear view mirror.
Use the Wiring Diagram Technical Note for the New Twingo.
Check the connection and condition (possible wiring damage) of the connector of component 1872.
If the connector is faulty (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for the
repair), repair the connector, otherwise replace the wiring.
With connector A of component 419 and connector of union R301 disconnected, check the insulation and
continuity of the following connections between components R301 (dashboard/interior lights intermediate union)
and 419.
●connection 38JN
●connection 38GZ
If the connection or connections are faulty (see Technical Note 6015A, Repairing electrical wiring, Wiring:
Precautions for repair), repair the wiring, otherwise replace it.
With the connector of component 1872 disconnected, check the insulation and continuity of the following
connections between components R301 (dashboard/interior lights intermediate union) and 1872.
●connection 38JN
●connection 38GZ
If the connection or connections are faulty (see Technical Note 6015A, Repairing electrical wiring, Wiring:
Precautions for repair), repair the wiring, otherwise replace it.
Check the insulation of connections 38JN and 38GZ of component 1872.
If the connection or connections are faulty and there is a repair procedure (see Technical Note 6015A, Electrical
wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check the resistance of component 1872 between connections 38JN and 38GZ.
Replace the sensor if the resistance is not 10 kΩΩ Ω Ω
± 500 ΩΩ Ω Ω
at 25 ˚C. For more details, consult the electrical
specifications of the sensor according to the temperature (see Help).
If the fault is still present, contact the Techline.
AFTER REPAIRClear the stored faults.
Follow the instructions to confirm repair.
Deal with any other faults.
CLIM_V44_DF007