2010 RENAULT SCENIC sensor

62A - 7
AIR CONDITIONING
Fault finding - Function architecture62A
V4
Air conditioning system design
The air conditioning system uses four computers. The four computers are connected by the multiplex system, except
in the case of manual air conditioning, where the connection between the air conditioning control panel and the UCH
is by normal wiring.
The air conditioning control panel interprets the driver's wishes and transmits them to the other computers; it also
manages the passenger compartment ventilation, air distribution, air mixing and air recirculation.
The UCH transmits the request to engage the air conditioning compressor to the injection and controls the operation
of the passenger compartment heating resistors (RCH).
The injection receives the refrigerant fluid pressure signal from the pressure sensor. The injection computer
authorises or inhibits the request to engage the compressor depending on how the vehicle is operating and transmits
the signal to the Protection and Switching Unit (UPC).
The role of the UPC is to manage the power section of the air conditioning system. It controls the engagement of the
compressor, the engine cooling fan units and the heated rear screen.
GLOSSARY
RCH = passenger compartment air heating resistors
AC control panelUCH
–interpretation of driver's
wishes
–passenger compartment
ventilation management
–air distribution management
–air mixing management–passenger compartment air
heating resistors operation
management
UPC
(Power and Switching Unit)Injection computer
–engine unit management
–
compressor control
–
heated rear screen control–air conditioning authorisation
Manual air conditioning
and
Climate controlAIR CONDITIONING
Fault finding - Function architecture
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$030.mif

62A - 10
AIR CONDITIONING
Fault finding - Mode of operation62A
V4MR-372-J84-62A000$010.mif
Manual air conditioning
and
Climate control
CLIM X84 1.1
Edition 2
Summary of components controlled or managed by the climate control computer
Ventilation and climate control unit
Passenger
compartment
blower
Vehicle multiplex
network
Passenger
compart-
ment blower
power
module
Recir-
culation
motorDistribution
motorMixing
motorInterior
temperature
sensor Solar radiation
sensor
Actuator control Sensor management
Climate control computer (control panel)
Climate control
management
(hot and cold)User requests
management
(buttons pressed) Button lighting
Key:
Wire connections =
Multiplex connections =
MR-372-J84-62A000$040.mif

62A - 13
AIR CONDITIONING
Fault finding - Mode of operation62A
V4MR-372-J84-62A000$010.mif
Summary of components controlled or managed by the UCH
Summary of components controlled or managed by the Protection and Switching Unit
Passenger
compartment
heating
resistors (RCH)
relay No. 2 Passenger
compartment
heating
resistors (RCH)
relay No. 1 Passenger compartment
heating resistors (RCH)
relay No. 3 (Scénic only)Exterior
temperature
sensor
Vehicle
multiplex
network
Actuator control Sensor management
UCH
Air conditioning request
managementHeated rear screen
control
managementPassenger compart-
ment heating resistor
control management
Engine cooling
fan unitHeated rear
screen and
heated door
mirrorsClimate control
compressorAlternator:
"DF"
terminal
Actuator control Electrical availability management
UPC
"DF" terminal signal formatting
(alternator charge)
Key:
Wire connections =
Multiplex connections =
Manual air conditioning
and
Climate control
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$040.mif

62A - 14
AIR CONDITIONING
Fault finding - Mode of operation62A
V4MR-372-J84-62A000$010.mif
Manual air conditioning
and
Climate control
Summary of components controlled or managed by the injection computer
Refrigerant fluid
pressure sensorEngine coolant
temperature
sensorVehicle
multiplex
network
Sensor management
Engine injection computer
Management of the cold loop (refrigerant fluid pressure,
switch on engine cooling fan request, compressor
engagement authorisation, etc.)Passenger compartment
heating resistors (RCH)
authorised power
management
Key:
Wire connections =
Multiplex connections =
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$040.mif

AIR CONDITIONING
Fault finding - Fault Finding Chart62A
62A-45V4 MR-372-J84-62A000$080.mif
Manual air conditioning
and
Climate controlAIR CONDITIONING
Fault finding - Fault Finding Chart
ALP 6 No heating or inadequate heating
NOTESOnly refer to this customer complaint after a full check with the diagnostic tool (fault
reading and configuration checks).
Is the air flow correct?
YES
Is the air distribution correct?
YES
With the engine warm, select the MAX heat position.
Is the blown air hot?
NO
Using the diagnostic tool statuses and parameters
screen (cold loop sub-function), check that the
temperature signals are correct (no sensor drift
resulting in incorrect measurement).
For manual air conditioning systems:
–External air temperature and engine coolant
temperature.
For climate control systems:
–External air temperature, engine coolant
temperature and internal air temperature.
Depending on the vehicle equipment, also check that
the internal air temperature sensor mini-turbine is
operating correctly (this can distort the measurement if
it is faulty).
Are the temperature signals consistent?
YES
NO
NO
YES
NOSee ALP 3, air flow fault.
See ALP 2, air distribution fault.
If necessary, explain how the
system works to the customer
again.
Carry out a conformity check on
the sensors (refer to the relevant
section).
Replace any faulty components.
AFTER REPAIRPerform a complete check using the diagnostic tool.
CLIM X84 1.1
Edition 2

AIR CONDITIONING
Fault finding - Fault Finding Chart62A
62A-47V4 MR-372-J84-62A000$080.mif
ALP 7 Too much hot air
NOTESOnly refer to this customer complaint after a full check with the diagnostic tool (fault
reading and configuration checks).
Is the air flow correct?
YES
Is the air distribution correct?
YES
Using the diagnostic tool statuses and parameters screen (cold loop sub-
function), check that the temperature signals are correct (no sensor drift
resulting in incorrect measurement).
For manual air conditioning:
External air temperature and engine
coolant temperature.
For regulated climate control systems:
External air temperature,
engine coolant temperature and internal air temperature.
Depending on the vehicle equipment, also check that the internal air
temperature sensor mini-turbine is operating correctly (this can distort the
measurement if it is faulty).
Are the temperature signals consistent?
YES
With the engine warm and
passenger compartment ventilation
operating, vary the position of the
mixing flap from the maximum hot
position to the maximum cold
position and check subjectively that
there is a difference in temperature.
Can you feel the difference in
temperature?
YESCarry out a
conformity check on
the sensors (refer to
the relevant section).
Replace any faulty
components.
For climate control systems:
Carry out a conformity check on the mixing motor (PR012
Mixing motor). If the conformity check does not reveal any
faults, look for a mechanical fault with the mixing flap
(condition of the motor's toothed sector, flap jammed inside the
unit, etc.).
For manual air conditioning systems:
Check the condition and routing of the mixing flap control
cable. Eliminate any constraints on it: kinks, cable restricted by
plastic clips, etc. Replace it if necessary. Unclip the cable from
the side of the unit and check the stiffness of movement of
each component: control button and flap control on the air
distribution unit.
Check that there is no mechanical fault with the mixing flap
(flap jammed inside the unit, etc.).
Carry out any necessary repairs.
Manual air conditioning
and
Climate control
NO
NO
NO
NOSee ALP 3, air flow fault.
See ALP 2, air distribution fault.
AFTER REPAIRPerform a complete check using the diagnostic tool.
CLIM X84 1.1
Edition 2

AIR CONDITIONING
Fault finding - Fault Finding Chart62A
62A-49V4 MR-372-J84-62A000$080.mif
Manual air conditioning
and
Climate control
ALP 8 No cold air
NOTESOnly carry out this conformity check after a full check with the diagnostic tool (fault
reading and configuration checks).
Using the diagnostic tool statuses and parameters screen (cold loop sub-
function), check that the temperature signals are consistent (no sensor drift
resulting in incorrect measurement).
For manual air conditioning:
External air temperature and engine
coolant temperature.
For regulated climate control systems:
External air temperature,
engine coolant temperature and internal air temperature. Depending on
the vehicle equipment, also check that the internal air temperature sensor
mini-turbine is operating correctly (this can distort the measurement if it is
faulty).
Are the temperature signals consistent?
YES
Start the engine and switch on the air conditioning by pressing the AC
button (with a request for maximum cold temperature and the passenger
compartment fan running).
View the following statuses on the user selection sub-function screen:
–For
climate control systems:
Status ET143 AIR CONDITIONING REQUEST 1 should display ACTIVE
and the symbol AC should be displayed on the air conditioning control panel
screen.
–For
manual air conditioning systems:
Status ET029 AIR CONDITIONING BUTTON should display PRESSED.
NOTE: these statuses show the request from the air conditioning control
panel to the UCH to start the air conditioning.
Are the correct statuses displayed?
YES
NOCarry out a
conformity check
on the sensors.
Replace any faulty
components.
NOContact your
Techline.
AFTER REPAIRPerform a complete check using the diagnostic tool.
CLIM X84 1.1
Edition 2

AIR CONDITIONING
Fault finding - Fault Finding Chart62A
62A-55V4 MR-372-J84-62A000$080.mif
Manual air conditioning
and
Climate control
ALP 9
CONTINUED
Using the diagnostic tool statuses and parameters screen
(cold loop sub-function), check that the temperature signals
are correct (no sensor drift resulting in incorrect
measurement).
For manual air conditioning:
External air temperature and
engine coolant temperature.
For regulated climate control systems:
External air
temperature, engine coolant temperature and internal air
temperature.
Depending on the vehicle equipment, also check that the
internal air temperature sensor mini-turbine is operating
correctly (this can distort the measurement if it is faulty).
Are the temperature signals consistent?
YES
With the engine warm and
passenger compartment
ventilation operating, vary the
position of the mixing flap
from the very cold position to
the very hot position and
check subjectively that there
is a difference in temperature.
Can you feel the difference
in temperature?
YES
Check the refrigerant fluid
level.
NO
NOCarry out a conformity
check on the sensors (refer
to the relevant section).
Replace any faulty
components.
For climate control systems:
Carry out a conformity check on the mixing motor (PR012
Mixing motor). If the conformity check does not reveal any
faults, look for a mechanical fault with the mixing flap (condition
of the motor's toothed sector, flap jammed inside the unit, etc.).
For manual air conditioning systems:
Check the condition and routing of the mixing flap control
cable. Eliminate any constraints on it: kinks, cable restricted by
plastic clips, etc. Replace it if necessary. Unclip the cable from
the side of the unit and check the stiffness of movement of
each component: control button and flap control on the air
distribution unit.
Check that there is no mechanical fault with the mixing flap
(flap jammed inside the unit, etc.).
Carry out any necessary repairs.
AFTER REPAIRPerform a complete check using the diagnostic tool.
CLIM X84 1.1
Edition 2