13B-14
MR-372-J84-13B200$108.mif
V13
DIESEL INJECTION
Fault finding – System operation
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
c) Functions hosted:
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 transition phases (e.g. high acceleration demand for overtaking, anti-stalling and moving off). These
conditions are only taken into account if they do not occur repeatedly, so as to prevent system instabilities
(erratic deactivation),
– when certain faults appear.
Cold loop air conditioning management (Mégane II only):
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 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.
– a "valving" function depending on the various engine functions: the damper valve closes by a few % in order to
create a venturi effect in the EGR valve flow section.
The aim of this is to accelerate the EGR gas flow rate and to reduce the emission of pollutants.
– regulatory function during the regeneration of the particle filter.
Thermoplunger management (only for Vdiag 58, 5C,18, 1C and 20):
This vehicle is fitted with thermoplungers. They are managed and activated by the injection system.
See configuration reading LC056 Thermoplungers: WITH or WITHOUT.
When necessary, the thermoplungers are actuated by the injection system only during particle filter
regeneration by means of a specific unit.
The maximum number of thermoplungers that can be managed is four; their activation depends mainly on the
coolant temperature (< 15°C) and air temperature (< 5°C).
13B-184
MR-372-J84-13B200$504.mif
V13
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5CDIESEL INJECTION
Fault finding – Interpretation of statuses13B
ET088
REQUEST TO START COMPRESSOR
STATUS DEFINITIONACTIVE: This status indicates that the compressor is engaged.
INACTIVE: This status indicates that the compressor is not engaged.
NOTESSpecial notes:
Only perform these tests if the statuses do not correspond with the system
programming functions.
Engine running, engine coolant temperature > 80 °C
ACTIVE
Status ET088 becomes ACTIVE if there has been a request for air conditioning (“AC” or
“AUTO” button pressed, with maximum cold) and if status ET004 Air conditioning
authorisation 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 compressor activation.
If the injection computer authorises compressor activation, it sends the compressor
activation request to the Protection and Switching Unit (Vdiag 18, 1C, 20 only) and
status ET088 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 compressor activation, it sends the compressor
activation request to the Protection and Switching Unit (Vdiag 18, 1C, 20 only) and
status ET088 becomes ACTIVE.
If there has been no compressor activation request and status ET088 remains ACTIVE
(see62A, Air conditioning).
Note:
Compressor operation is only authorised when the engine is running.
Compressor switch-on is finally requested by the Protection and Switching
Unit (Vdiag 18, 1C, 20 only).
AFTER REPAIRCarry out a road test followed by a check with the diagnostic tool.
EDC16_V50_ET088/EDC16_V58_ET088/EDC16_V5C_ET088/EDC16_V18_ET088/EDC16_V1C_ET088/EDC16_V20_ET088
