DIESEL INJECTION
Fault finding – Introduction13B
13B - 6V3 MR-372-J84-13B250$045.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
5. FAULT FINDING LOG
You will always be asked for this log:
●when requesting technical assistance from Techline,
●for approval requests when replacing parts for which approval is mandatory,
●to be attached to monitored parts for which reimbursement is requested. The log is needed for warranty
reimbursement, and enables better analysis of the parts removed.
6. SAFETY ADVICE
Safety rules must be observed during any work on a component to prevent any damage or injury:
–make sure that the battery is properly charged to avoid damaging the computers with a low load,
–use the appropriate tools.
7. CLEANLINESS ADVICE TO FOLLOW WHEN CARRYING OUT OPERATIONS ON THE HIGH PRESSURE
DIRECT INJECTION SYSTEM
Risks relating to contamination
The system is highly sensitive to contamination. The risks associated with contamination are:
–damage to or destruction of the high pressure injection system and the engine,
–a component seizing or leaking.
All After-Sales operations must be performed under very clean conditions. This means that no impurities (particles a
few microns in size) should be allowed to penetrate the system during dismantling or get into the circuits via the fuel
unions.
The cleanliness guidelines must be applied from the filter through to the injectors.IMPORTANT!IMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools. The
FAULT FINDING LOG, which should be completed during the procedure, enables you to keep
track of the procedure which is carried out. It is an essential document when consulting the
manufacturer.
IT IS THEREFORE COMPULSORY TO COMPLETE A FAULT FINDING LOG
EVERY TIME A FAULT FINDING PROCEDURE IS PERFORMED
DIESEL INJECTION
Fault finding – Cleanliness guidelines13B
13B - 7V3 MR-372-J84-13B250$033.mif
EDC16
PROGRAM NO.: C1
Vdiag No.: 51DIESEL INJECTION
Fault finding – Cleanliness guidelines
I - RISKS ASSOCIATED WITH CONTAMINATION
The high pressure direct injection system is highly sensitive to contamination. The risks associated with
contamination are:
–damage to or destruction of the high pressure injection system,
–components jamming,
–a component leaking.
All After-Sales operations must be performed under very clean conditions. This means that no impurities (particles a
few microns in size) should have entered the system during dismantling.
The cleanliness principle must be applied from the filter to the injectors.
What are the sources of contamination?
metal or plastic swarf,
–paint,
–fibres:
–from cardboard,
–from brushes,
–from paper,
–from clothing,
–from cloths,
–foreign bodies such as hair,
–ambient air,
–etc.
II - NOTES TO BE FOLLOWED BEFORE ANY OPERATION
Check that you have plugs for the unions to be opened (set of plugs available from the Parts Department). The plugs
are single-use only. After use, they must be discarded (once used they are soiled and cleaning is not sufficient to
make them reusable). Unused plugs must be discarded.IMPORTANT
Cleaning the engine using a high pressure washer is prohibited because of the risk of damaging connections. In
addition, moisture may collect in the connectors and create electrical connection faults.
IMPORTANT
Before any work is carried out on the high pressure injection system, protect:
–the accessories and timing belts,
–the electrical accessories, (starter, alternator, electric power-assisted steering pump),
–the flywheel surface, to prevent any diesel from running onto the clutch friction plate.
MR-372-J84-13B250$033.mif
DIESEL INJECTION
Fault finding – System operation13B
13B - 9V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51DIESEL INJECTION
Fault finding – System operation
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 112-track BOSCH EDC16 C3 type computer.
The system is comprised of:
–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 coolant temperature sensor,
–a cylinder reference sensor,
–an engine speed sensor,
–a turbocharger pressure sensor,
–an accelerator pedal potentiometer,
–an EGR solenoid valve,
–an atmospheric pressure sensor integrated into the injection computer,
–an air flow sensor with an air temperature sensor,
–a turbocharging pressure limitation solenoid valve,
–a motorised damper valve.
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 fuel supplied, according to the requirement determined by the computer. The rail
supplies each injector through a steel pipe.
MR-372-J84-13B250$135.mif
DIESEL INJECTION
Fault finding – System operation13B
13B - 10V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
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.
Determines the injection duration necessary for supplying the correct quantity of diesel and the moment when
injection is required; controls each injector electrically and individually after determining these 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 CMV control via the Protection and Switching Unit (centralised coolant temperature management function),
–the air conditioning (cold loop function),
–the cruise control/speed limiter function,
–pre-post heating control,
–fault warning lights via the multiplex network.
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 fuel flow actuator enables the high
pressure pump to supply the exact quantity of diesel fuel required to maintain the rail pressure. 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.
DIESEL INJECTION
Fault finding – System operation13B
13B - 11V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
b) Multiplex connection between the different vehicle computers.
The electronic system fitted in this vehicle is multiplexed.
This enables dialogue between the various vehicle computers. As a result:
–the activation of the fault warning lights on the instrument panel is performed by the multiplex network, with the
vehicle speed sensor on the gearbox deactivated,
–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 transmitted by the ABS computer via a wire connection, then
sent out on the multiplex network by the instrument panel. The vehicle speed signal is used mainly by the injection
computer and the airbag computer.
Some vehicles have adopted a sensor for detecting water in the diesel fuel, located in the filter. 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 actuator, the 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 fails, the pressure sensor, the rail and the five high pressure pipes must be replaced.
It is forbidden to remove any injection pump pulley bearing the number 070 575. If the pump needs to be replaced,
replace the pulley.
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.
DIESEL INJECTION
Fault finding – System operation13B
13B - 15V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
EOBD* management:
The OBD (On Board Diagnostic) system enables the detection of any faults relating to the vehicle emission control
system (OBD EURO IV emission control standards exceeded).
This system should be active for the entire life of the vehicle.
1. Conditions causing an OBD fault
An OBD fault will be detected after 3 driving cycles and the following parameters will be registered in the computer:
–engine load,
–vehicle speed
–air temperature
–coolant temperature,
–turbocharging pressure,
–rail pressure,
–air flow,
–distance travelled in miles by the vehicle since activation of the OBD warning light.
It allows the driver to know whether the vehicle has a fault directly linked to the emission control system.
2. System faults indicated by the OBD
Only a few faults are indicated by the OBD system:
–DF001 Coolant temperature sensor circuit.
–DF003 Atmospheric pressure sensor circuit.
–DF011 Sensor feed voltage no. 1.
–DF012 Sensor feed voltage no. 2.
–DF013 Sensor feed voltage no. 3.
–DF038 Computer in 6.DEF EEPROM fault.
–DF040 Cylinder 1 injector circuit in CO Open circuit.
–DF041 Cylinder 2 injector circuit in CO Open circuit.
–DF042 Cylinder 3 injector circuit in CO Open circuit.
–DF043 Cylinder 4 injector circuit in CO Open circuit.
–DF054 Turbocharging solenoid valve control circuit in CC.0 Short circuit to earth.
–DF056 Air flow sensor circuit.
–DF209 EGR valve position sensor circuit.
–DF621 EGR valve jammed open.
Some repair operations require programming to ensure that certain engine components function correctly.
Follow the programming procedures (see Replacement of components), if replacing the exhaust gas
recirculation valve or an injector.
*EOBD: Electronic on board diagnostics
DIESEL INJECTION
Fault finding – Allocation of computer tracks13B
13B - 19V3 MR-372-J84-13B250$180.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
3 - Grey 32-track connector C
Track Description
A1Not used
A2Water in diesel detection sensor signal
A3Alternator charge signal
A4Preheating unit diagnostic signal
B1Not used
B2Not used
B3Not used
B4Not used
C1Not used
C2EGR valve position potentiometer earth
C3Refrigerant pressure sensor earth
C4Not used
D1Not used
D2Not used
D3Not used
D4Not used
E1Turbocharging pressure solenoid valve control
E2Preheating unit control
E3Not used
E4Not used
F1Not used
F2Not used
F3Not used
F4Not used
G1Injector 4 feed
G2Injector 2 feed
G3Injector 1 control
G4Injector 2 control
H1Injector 1 feed
H2Injector 3 feed
H3Injector 4 control
H4Injector 3 control
DIESEL INJECTION
Fault finding – Replacement of components13B
13B-20V3 MR-372-J84-13B250$225.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51DIESEL INJECTION
Fault finding – Replacement of components
COMPUTER REPLACEMENT OR REPROGRAMMING
Operations to be carried out before reprogramming the injection computer:
Before reprogramming the injection computer, move the main CC/SL switch to the rest position. The information
about the cruise control or the speed limiter displayed on the instrument panel disappears.
Otherwise, if the main switch remains in the cruise control or speed limiter position during and after reprogramming,
the Cruise control/Speed limiter function will not be operational.
The procedure for resetting the function is as follows:
–Vehicle ignition on.
–Move the cruise control/speed limiter switch to the rest position (the computer detects the rest position at that
moment).
–Move the cruise control/speed limiter switch to the Cruise control position to activate the Cruise control function.
–Move the cruise control/speed limiter switch to the Speed limiter position to activate the Speed limiter function.
Two operations must be performed when replacing or reprogramming the computer:
SC003 Save computer data and SC001 Enter saved data.
–Use SC003 before the computer is replaced or reprogrammed. This enables certain data to be saved in the
diagnostic tool so that the new computer* can be reconfigured like the old one. The saved data are: injector
codes, EGR programming, vehicle options.
–Run SC001 after the computer is replaced or reprogrammed. It enables you to rewrite the data (saved by
command SC003) to the new computer*.
If you cannot establish dialogue with the computer being replaced: you will not be able to save anything. After
replacing the computer, enter the IMA code of each injector manually, reading the code on each injector (see
INJECTOR REPLACEMENT).
Exhaust gas recirculation valve data is programmed automatically the 1
st time the new computer is switched on*.
* new computer or reprogrammed computer. IMPORTANT
–Switch on the diagnostic tool (mains or cigarette lighter supply).
–Connect a battery charger.
–Switch off all electrical consumers (lights, interior lights, air conditioning, radio/CD, etc.).
–Wait for the engine to cool (engine coolant temperature < 60˚ and air temperature < 50˚).
–The GMV are activated automatically when the computer is being reprogrammed.