climate control RENAULT SCENIC 2009 J84 / 2.G Engine And Peripherals EDC16 Workshop Manual

DIESEL INJECTION
Fault finding – System operation13B
13B - 12V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
c) Hosted functions:
Air conditioning management assistance:
In the case of vehicles with climate control, the EDC16 system has the option of deactivating the air conditioning via
the UCH, under certain conditions of use:
–when requested by the driver,
–when starting the engine,
–if the engine overheats (in order to reduce the power the engine has to supply),
–when the engine speed is kept at a very high level (to protect the compressor),
–during transitory phases (such as demands for high acceleration when overtaking, anti-stall and start-up) These
conditions are only taken into account when they do not occur repeatedly, to prevent instability in the system
(erratic deactivations),
–when certain faults appear.
Cold loop air conditioning management:
The air conditioning is the cold loop type and its management shared between several computers.
The injection computer is responsible for:
–authorising cold requests according to the refrigerant pressure, the engine coolant temperature and the engine
speed,
–calculating the power absorbed by the compressor (from the refrigerant pressure),
–requesting operation of the GMV, from the UPC, according to the vehicle speed, the refrigerant pressure and the
engine coolant temperature.
The driver requests the air conditioning to be switched on by means of the ventilation selector coupled to a switch.
The cold air request is authorised or denied depending on the pressure measured. If this pressure is outside the
operating limits, the cold loop program is not activated.
Management of the damper valve:
The damper valve currently has three functions:
–the valve closes in order to block the passage of air towards the cylinders to shut off the engine. The aim of this is
to stop the engine as quickly as possible and to reduce instabilities as the engine is switched off.
–"valving" function depending on the engine operation: the damper valve closes by a few % to create a ''venturi''
effect at the EGR valve passage section.
The aim of this is to accelerate the air flow of EGR gases and to reduce the emission of pollutants.

DIESEL INJECTION
Fault finding – Interpretation of statuses13B
13B - 174V3 MR-372-J84-13B250$630.mif
NO
EDC16
PROGRAM NO.: C1
Vdiag No.: 51
ET004
AC AUTHORISED
NOTESSpecial notes:
Only perform these tests if the statuses do not correspond with the system
programming functions.
YES
The air conditioning authorisation only changes to YES if:
–the air conditioning request has been made by the driver (air conditioning switch in
AC or AUTO position with minimum ventilation),
–the engine is not under full load,
–the air conditioning system is not faulty.
Status ET004 remains at NO under the following conditions:
–Vehicle stopped with the ignition on,
–faults present in the air conditioning circuit,
–no air conditioning request made by the driver,
–engine under full load.
If status ET004 remains NO then the air conditioning should be authorised; check:
–that the air conditioning compressor is activated correctly,
–the air conditioning system supply fuses,
–the presence of refrigerant in the air conditioning circuit,
–that the refrigerant fluid pressure value is consistent at idle speed.
If the fault is still present, check the climate control computer faults (see 62C, Air
conditioning).
AFTER REPAIRCarry out a road test followed by a complete test with the diagnostic tool.
EDC16_V51_ET004

DIESEL INJECTION
Fault finding – Interpretation of statuses13B
13B - 187V3 MR-372-J84-13B250$630.mif
INACTIVE
EDC16
PROGRAM NO.: C1
Vdiag No.: 51
ET088
REQUEST TO START COMPRESSOR
NOTESSpecial notes:
Only perform these tests if the statuses do not correspond with the system
programming functions.
ACTIVE
Status ET088 becomes ACTIVE if there has been a request for air conditioning (press
the AC or AUTO button, with maximum cold) and if status ET004 is YES.
The selection is made on the air conditioning control panel, the request for air
conditioning is transmitted to the UCH which in turn transmits the request to the injection
computer which either authorises or does not authorise the compressor to switch on. If
the injection computer authorises the compressor to switch on, its sends the
compressor on request to the UPC and status ET088 COMPRESSOR ON REQUEST
becomes ACTIVE (Climate control).
If the vehicle is equipped with manual air conditioning, the air conditioning request is
transmitted from the air conditioning control panel to the UCH which then accepts or does
not accept the air conditioning compressor coming on depending on the operating status
of the passenger compartment fan. When the request has been accepted, the request
to switch on the compressor is transmitted to the injection computer which either
authorises or does not authorise the compressor to start.
If the injection computer authorises the compressor to switch on, its sends the
compressor on request to the UPC and status ET088 COMPRESSOR ON REQUEST
becomes ACTIVE.
If there has been no compressor on request and status ET088 remains ACTIVE
(see 62A, Air conditioning).
Note:
Switching on the compressor is only authorised when the engine is running.
Switching on the compressor is ultimately controlled the UPC.
Status ET088 is INACTIVE when there has been no air conditioning request and
when the compressor has not been authorised to come on (ET004 is NO or when
the driver turns off the air conditioning).
If there has been no compressor on request and status ET088 remains INACTIVE (see
62A, Air conditioning).
Note:
Switching on the compressor is only authorised when the engine is running.
Switching on the compressor is ultimately controlled the UPC.
AFTER REPAIRCarry out a road test followed by a complete test with the diagnostic tool.
EDC16_V51_ET088