13B-18V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
b. The connections between the vehicle's various computers are multiplexed.
The electronic system fitted in this vehicle is multiplexed.
It enables dialogue between the various vehicle computers. As a result:
– the fault warning lights on the instrument panel are lit by the multiplex network,
– vehicle faults are displayed by the multiplex network,
– the vehicle speed sensor on the gearbox is not needed.
The vehicle speed signal on the instrument panel is sent by the ABS computer via the multiplex network. The vehicle
speed signal is mainly used by the injection computer, the airbag computer and the automatic transmission
computer (if the vehicle is fitted with this).
c. Functions hosted:
Air conditioning management assistance:
For vehicles with air conditioning, the EDC16C36 system provides 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. under heavy acceleration when overtaking, anti-stalling and moving off strategies).
These conditions are only taken into account when they do not occur repeatedly, in order to prevent system
instabilities (erratic deactivations), when certain faults appear.
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.
Thermoplunger management (only on certain F9Q816 engines in VDiag 48):
This vehicle is fitted with thermoplungers. They are managed and activated by the injection system.
There are two types of program:
– controlled by the injection system during particle filter regeneration,
– passenger compartment function; the air conditioning requests the injection to activate one or more thermoplungers
to raise the air temperature in the passenger compartment. The injection computer authorises the actuation or non-
actuation of the thermoplungers according to the operating phases and the power requirements of the engine.
The maximum number of thermoplungers that can be actuated is four. Their actuation depends mainly on the
coolant temperature (< 15°C) and the air temperature (< 5°C).
