13B-15V9 MR-372-J84-13B450$050.mif
13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
System outline
The high pressure injection system is designed to deliver a precise quantity of diesel fuel to the engine at a set
moment.
It is fitted with a BOSCH 128-track computer, type EDC16C36.
The system comprises:
– a priming bulb on the low pressure circuit,
– a diesel filter,
– a high pressure pump with a built-in low pressure pump (transfer pump),
– a high pressure regulator mounted on the pump,
– an injector rail,
– a diesel fuel pressure sensor built into the rail,
– four solenoid injectors,
– a diesel temperature sensor,
– a coolant temperature sensor,
– a cylinder reference sensor,
– an engine speed sensor,
– a turbocharger pressure sensor,
– an accelerator pedal potentiometer,
– an exhaust gas recirculation solenoid valve,
– a recycled gas cooling solenoid valve,
– an atmospheric pressure sensor integrated into the injection computer,
– an air flowmeter fitted with an air temperature sensor,
– a turbocharging pressure limitation solenoid valve,
– a motorised damper valve,
– a particle filter (F9Q816 engine only),
– a particle filter differential pressure sensor (F9Q816 engine only),
– a temperature sensor upstream of the particle filter (F9Q816 engine only),
– a temperature sensor downstream of the particle filter (only on certain F9Q816 engines in VDiag 48),
– a temperature sensor upstream of the turbine (F9Q816 engine only),
– a richness ratio sensor,
– a turbocharger cooling pump.
The common rail direct high pressure injection system works sequentially (based on the petrol engine multipoint
injection).
This injection system reduces operating noise, reduces the volume of pollutant gases and particles and produces
high engine torque at low engine speeds thanks to a pre-injection procedure.
The high pressure pump generates the high pressure and transmits it to the injector rail. The actuator located on the
pump controls the quantity of diesel supplied, according to the demand determined by the computer. The rail
supplies each injector through a steel pipe.
DIESEL INJECTION
Fault finding – Features
13B-16V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
The high pressure pump is supplied at low pressure by an integrated low pressure pump (transfer pump).
It supplies the rail, the pressure of which is controlled by the fuel flow actuator (MPROP) for charging, and for
discharging by the injector valves. This compensates for pressure drops. The flow actuator allows the high pressure
pump to supply the exact quantity of diesel fuel required to maintain the pressure in the rail. This component
minimises the heat generated and improves engine output. In order to discharge the rail using the injector valves,
the valves are controlled by brief electrical pulses which are:
– short enough not to open the injector (passing through the feedback circuit from the injectors),
– long enough to open the valves and discharge the rail.
Some vehicles have a presence sensor mounted in the filter for detecting water in the diesel. If there is water in the
diesel fuel, the orange “Injection and pre-post heating” warning light will come on.
The system can inject diesel fuel into the engine at a pressure of up to 1600 bar. Before each operation, check that
the injector rail is depressurised and that the fuel temperature is not too high.
You must respect the cleanliness guidelines and safety advice specified in this document for any work on the high
pressure injection system.
Removal of the internal parts of the pump and injectors is prohibited. Only the fuel flow regulator/actuator, diesel fuel
temperature sensor and the venturi can be replaced.
For safety reasons, it is strictly prohibited to undo a high pressure pipe union when the engine is running.
It is not possible to remove the pressure sensor from the fuel rail because this may cause circuit contamination
faults. If the pressure sensor is defective, replace the pressure sensor, rail and high pressure pipes associated with
the rail.
Supplying + 12 V directly to any component in the system is prohibited.
Ultrasonic decoking and cleaning are prohibited.
Never start the engine unless the battery is connected correctly.
Disconnect the injection computer when carrying out any welding work on the vehicle. WARNING
The engine must not operate with:
– Diesel fuel containing more than 10% diester,
– petrol, even in tiny quantities.
13B-17V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
a. The computer:
Determines the value of injection pressure necessary for the engine to operate correctly and then controls the
pressure regulator.
Checks that the pressure value is correct by analysing the value transmitted by the pressure sensor located on the
rail.
It determines the injection timing required to deliver the right quantity of diesel fuel and the moment when injection
should start. Controls each injector electrically and individually after determining these two values.
The flow injected into the engine is determined by:
– the duration of injector control,
– the rail pressure (regulated by the computer),
– the injector opening and closing speed,
– the needle stroke (determined by a constant for the type of injector),
– the nominal hydraulic flow of the injector (specific to each injector).
The computer manages:
– idling regulation,
– exhaust gas flow reinjection to the inlet (EGR),
– fuel supply check (advance, flow and rail pressure),
– the fan assembly control,
– the air conditioning (cold loop function),
– the cruise control/speed limiter function,
– pre-post heating control,
– indicator lights control via the multiplex network,
– the catalysed particle filter operation (F9Q816 engine only).
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).
13B-20V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Exhaust gas recirculation management:
The EGR (Exhaust Gas Recirculation) system involves removing exhaust gases and reintroducing them into the
inlet.
The exhaust gases are collected in the exhaust manifold (before the turbocharger), then directed to the EGR cooler
and the EGR valve.
EGR cooler
The EGR cooler bypass function cools the gases extracted from the exhaust via a gas-water exchanger and then
reintroduces the gases at the inlet. This cooler is equipped with an all-or-nothing solenoid valve, which enables
gases to be cooled or not cooled, depending on the emission control requirements.
EGR valve
The system comprises a direct current EGR valve and a potentiometer which reports the position of the valve.
A positive command controls its opening (0 → 100%).
The potentiometer serves to control and run fault finding on the valve.
The very first time the engine is started, then each subsequent engine start, the “valve closed” position is
programmed (offset). This value is compared to the very first offset or last programmed offset, for the purposes of
fault finding. It is also used to readjust the valve control function. This is why it is important to associate the EGR
valve to the computer which controls it.
Richness ratio sensor management (only on certain F9Q816 engines in VDiag 48):
The richness ratio sensor is mounted in the turbo outlet.
Its function is to reset the injection system drift.
The injection computer does not control the sensor immediately when the engine has just been started:
–ET300 Richness regulation is INACTIVE,
–PR779 Richness ratio sensor is equal to 1.
After a length of time that depends on the coolant temperature, with the engine running and in the absence of no
load conditions, the injection computer authorises the heating of the sensor:
–ET300 Richness regulation changes to ACTIVE,
– in about ten seconds, the PR778 Richness ratio sensor temperature increases to approximately 780°C,
– then the PR779 Richness ratio sensor displays a value of 0.3 ±0.1 at idle speed.
The turbocharger cooling pump:
Because of its high rotation speed, the turbocharger does not use ball bearings to ensure the pivot connection but
uses a bearing whose friction is reduced thanks to a pressurised film of oil.
When the engine is switched off, the oil is no longer under pressure and no longer provides the pivot connection. A
quantity of oil therefore remains, which collects around the bearing.
When the turbocharger is in operation, the bearing is subjected to high temperatures. After the engine is switched
off, the slow decrease in temperature heats the stagnant oil. This then modifies the viscosity of the oil and therefore
increases the risk of the turbocharger sticking.
To prevent this, a turbocharger coolant pump circulates coolant to lower the temperature of the turbocharger. It is
electrically activated for 5 mins if the engine coolant temperature exceeds 80°C. In addition, the coolant circulation
prevents deterioration of the liquid properties by stopping it collecting under the same temperature constraints as the
oil.
13B-21V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Catalysed particle filter management (for F9Q816 engine only):
The particle filter prevents the escape of carbon particles emitted by the engine but not yet removed from the
exhaust gases.
The particle filter is a microporous structure containing channels arranged so as to force-filter the exhaust gases.
The exhaust pipe consists of several components:
– an oxidation catalytic converter mounted after the turbocharger. This catalytic converter ensures that HC/CO levels
meet current standards by generating the heat (rise in exhaust temperature caused by catalysis) required for
particle filter regeneration.
– a particle filter located under the body,
– a differential pressure sensor to inform the computer of the pressure difference upstream and downstream of the
particle filter
– a particle filter upstream temperature sensor,
– a particle filter downstream temperature sensor (only on certain F9Q816 engines in VDiag 48),
– a temperature sensor upstream of the turbine (TAVT).
During driving, the particle filter becomes loaded with particles of soot. When a given weight of soot determined by
computer mapping is reached, regeneration mode can be triggered if the maximum weight of soot in the particle filter
has not been reached and the engine operating conditions are met (coolant temperature, etc.)
Particle filter regeneration consists of burning the particles of soot that have accumulated in the filter.
The differential pressure sensor measures the particle filter inlet/outlet pressure differential; this measurement is
used to estimate the weight of soot present in the particle filter by mapping in the computer:
(soot weight = pressure differential as a function of exhaust volume flow rate).
13B-22V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
If all the criteria are met, the computer enters regeneration mode. The injection programming is adjusted in order to
raise the target exhaust gas temperature between 550 and 650°C.
This temperature allows the particles accumulated in the filter to be partially or completely burnt (regenerated).
Regeneration efficiency depends on the particle filter inlet temperature and the time spent in regeneration mode.
Regeneration can be carried out automatically when driving if the weight of soot is less than 70 g and if the number
of regeneration attempts when driving is less than 11 (only for Vdiag 48).
If the weight of soot is greater than 70 g, the user will have to request an After-sales regeneration.
This regeneration is carried out in the workshop. Always follow the instructions written in the interpretation of
commands (SC017 Particle filter regeneration) to perform regeneration in complete safety.
After an After-sales regeneration, always reconfigure certain parameters in the computer using command SC036
Reinitialise programming (see "interpretation of commands").
Warning light management:
Instrument panel display
The computer displays certain information on the instrument panel relating to engine operation. This involves six
functions:
– the pre-postheating warning light,
– the coolant temperature warning message,
– the level 1 fault warning light (non-critical fault),
– the level 2 fault warning light (emergency stop),
– the OBD warning light (European On Board Diagnostic),
– the particle filter specific warning light (F9Q816 engine only).
These six functions are represented by 6 warning lights and/or messages displayed by the on-board computer.
In addition, certain warning lights are, when lit, accompanied by a spoken message on vehicles fitted with a voice
synthesiser (refer to the driver's handbook).
A 3 second visual inspection (automatic test procedure managed by the instrument panel) is carried out by the
injection computer when the ignition is switched on.IMPORTANT
The particle filter must be replaced after a period of time which largely depends on the grade of engine oil used -
this information is in the driver's handbook.
After replacing it, always reconfigure certain parameters in the computer using command SC036 Reinitialise
programming (see "interpretation of commands").
13B-23V9 MR-372-J84-13B450$050.mif
DIESEL INJECTION
Fault finding – Features13B
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Orange pre-postheating warning light
This warning light is used as an in-operation indicator lamp:
– Continuously lit under + after ignition feed: indicates preheating of the heater plugs.
It goes out when preheating is complete and the engine is able to start.
Orange "SERVICE" non-critical fault warning light (level 1)
This warning light is used to indicate a fault in the system:
– Continuously lit with the CHECK INJECTION message:
Indicates a level 1 fault (involving operation of the injection system in defect mode).
The driver should have the repairs carried out as soon as possible.
Temperature/red emergency STOP (level 2) warning light
This indicator light is used both as an in-operation indicator light and as a system fault warning light.
– Intermittently lit with the ENGINE OVERHEATING message:
Indicates that the coolant temperature is too high (the driver is free to stop the vehicle or not).
– Continuously lit with the INJECTION FAULT: STOP THE ENGINE message and an audible beep indicates a level
2 fault.
In that case, the vehicle must be stopped immediately (when traffic conditions allow).
The driver should carry out repairs as soon as possible.
European On Board Diagnostic excess pollution ORANGE warning light
Engine symbol with the CHECK EMISSION CONTROL message.
This warning light comes on if the system has one or more OBD faults.
This warning light is used to alert the driver to injection faults that could lead to excessive pollution, or if the EOBD
system (European On Board Diagnostic) has been deactivated.
The injection computer requests illumination of the OBD warning light for a present fault only after three successive
driving cycles.
The driver should have the repairs carried out as soon as possible.