13B-8V4 MR-372-J84-13B000$020.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
System outline
The DDCR injection system used on the K9 engine is an electronically managed high pressure injection system.
The fuel is compressed by a high pressure pump then stored in a rail that feeds the injectors. Injection occurs when
a current pulse is applied to the injector holders. The injected flow is proportional to the rail pressure and to
the applied pulse length, and the start of injection is phased with the start of the pulse.
The circuit comprises two subsystems, which are distinguished by the fuel pressure level.
– The low pressure system includes the tank, diesel fuel filter, transfer pump and injector holder return pipes.
– The high pressure circuit contains the high pressure pump, the rail, the injector holders and the high pressure tubes.
Finally, there are a certain number of sensors and regulating actuators for controlling and monitoring the entire
system.
Functions provided
Function: Fuel supply management (timing, flow and pressure).
Quantity of fuel injected and injection timing adjustment
The injection checking parameters are the quantities to be injected and their respective timing. These are calculated
by the computer using signals from the following sensors:
• Engine speed (Crankshaft + Cam for synchronisation)
• Accelerator pedal
• Turbocharging pressure and air temperature (Turbocharger pressure)
• Coolant temperature
• Air temperature
• Air load (Flow and Pressure)
• Rail pressure
• Flowmeter
• Turbocharging solenoid valve
The quantities to be injected and their respective timing are converted into:
• a reference tooth
• the time between this tooth and the start of the pulse
• the time for which the supply to the injector holder is on
An electrical current (pulse) is sent to each injector holder according to previously calculated data. The system
makes one or two injections (1 pilot injection, 1 main injection). The general principle is to calculate an overall
injected flow which will then be divided into a main injection flow and a pilot injection flow, to help the combustion
process work properly and to reduce pollutant emissions.
An accelerometer is used to monitor some of the fuel injection deviation. This has several roles:
• Protecting the engine by detecting injection leaks (disabled on the basic vehicle).
• Checking the pilot quantity by measuring deviation and dispersion
• By changing both the duration and timing of the injection, the quantity of fuel injected and the mixture ignition timing
can be adjusted.
DIESEL INJECTION
Fault finding – System operation
13B-9V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
Rail pressure check
The quality of combustion is influenced by the size of the atomised droplets in the cylinder. In the combustion
chamber, smaller fuel droplets will have time to burn fully, and will not produce smoke or unburned particles. To
meet the pollution requirements, the droplet size, and therefore the size of the injection holes, must be reduced.
With smaller holes, less fuel will be able to be introduced at a given pressure, which limits the power. To handle this
drawback, the injected fuel flow has to be increased, which means a pressure increase (and more apertures on the
injector nozzles). For the DDCR injection system, the pressure reaches 1400 bar in the rail, and must be constantly
regulated. The measuring circuit consists of an active pressure sensor on the rail connected to an analogue port on
the computer.
The High Pressure pump is supplied at low pressure (5bar) by a built-in transfer pump. This pump supplies the rail.
The rail filling pressure is controlled by the filling valve (IMV) and the discharge pressure is controlled by the injector
valves. This compensates for pressure drops. The filling actuator enables the high pressure pump to supply just
the exact quantity of diesel fuel required to maintain the rail pressure. This mechanism minimises the heat
generated and improves engine output.
In order to discharge the rail using the injector valves, the valves are actuated by short electrical pulses which are:
– short enough not to open the injector (and pass through the return circuit from the injectors),
– long enough to open the valves and discharge the rail.
The fuel surplus is sent back to the fuel filter or the tank, according to its flow. If there is no IMV control, the rail
pressure is limited by a discharge valve fitted on the pump.
Idling speed regulation
The computer handles the calculation of idling speed. This has to take account of the instantaneous power level to
be supplied, according to the following factors:
– Engine coolant temperature
– Gear engaged
– Battery charging
– Electrical consumers (Heating elements, Air conditioning, Fan assembly, Heated windscreen, etc.) active or
inactive
Individual injector correction (C2I)
The DDCR system injectors must be calibrated with corrective values to adjust their flow precisely. Each injector is
calibrated for different pressures on a test bench, and its specifications are shown on a label attached to the body of
the injector holders. These individual correction values are then written to the computer EEPROM, which can then
actuate the injectors by taking into account their manufacturing dispersion.
13B-16V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
48-TRACK BROWN CONNECTOR B
Description Tracks Tracks Description
Flowmeter supply (728, 729) A1 G1 Knock sensor earth (pinking)
Flowmeter signal (728, 729) A2 G2 Fuel temperature signal
Flowmeter earth (728, 729) A3 G3 Fuel temperature sensor earth
Cylinder 1 injector + control A4 G4 Cylinder 4 injector + control
EGR feedback potentiometer supply B1 H1 Not used
EGR feedback potentiometer signal B2 H2 Coolant temperature signal
EGR feedback potentiometer earth B3 H3 Coolant temperature sensor earth
Cylinder 1 injector - control B4 H4 Cylinder 4 injector - control
Turbocharging pressure sensor supply C1 J1 Not used
Turbocharging pressure sensor signal C2 J2 Inlet air temperature signal
Turbocharging pressure sensor earth C3 J3 Inlet air temperature earth (722)
Cylinder 2 injector + control C4 J4 Not used
Rail pressure sensor supply D1 K1 Accelerometer shielding (pinking)
Rail pressure sensor signal D2 K2 External air temperature signal
Rail pressure sensor earth D3 K3 External air temperature earth
Cylinder 2 injector - control D4 K4 Not used
Not used E1 L1 Not used
Phase sensor signal (cylinder) E2 L2 Not used
Phase sensor earth (cylinder) E3 L3 EGR valve control
Cylinder 3 injector + control E4 L4 Not used
Knock sensor signal (pinking) F1 M1 Not used
Engine speed (TDC) sensor + signal F2 M2Turbocharging solenoid valve control
(728, 729)
Engine speed sensor earth (TDC) F3 M3 Not used
Cylinder 3 injector - control F4 M4 Fuel flow actuator control
13B-22V4 MR-372-J84-13B000$050.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
Tool faultAssociated
DTCDiagnostic tool title
DF001 0115 Coolant temperature sensor circuit
DF002 0070 Air temperature sensor circuit (728, 729)
DF003 2226 Atmospheric pressure sensor circuit
DF005 0335 Engine speed sensor circuit.
DF007 0190 Rail pressure sensor circuit
DF008 0225 Pedal potentiometer circuit track 1
DF009 2120 Pedal potentiometer circuit track 2
DF010 0409 EGR position sensor circuit
DF014 0500 Vehicle speed information circuit
DF015 0685 Main relay control circuit
DF016 0403 EGR control circuit
DF017 0382 Preheating unit control circuit
DF024 0231 Low pressure actuator control circuit
DF025 0380 Preheater unit diagnostic connection
DF026 0201 Cylinder 1 injector control circuit
DF027 0202 Cylinder 2 injector control circuit
DF028 0203 Cylinder 3 injector control circuit
DF029 0204 Cylinder 4 injector control circuit
DF037 0513 Engine immobiliser
DF038 0606 Computer
DF039 0110 Inlet air temperature sensor circuit
DF047 0560 Computer feed voltage
DIESEL INJECTION
Fault finding – Fault summary table
13B-38
AFTER REPAIRDeal with any faults displayed by the diagnostic tool. Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V4 MR-372-J84-13B000$061.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DDCR INJECTION
Vdiag No.: 44, 48
DF024
PRESENTLOW PRESSURE ACTUATOR CONTROL CIRCUIT (IMV)CO.0: Open circuit or short circuit to earth.
CC.1: Short circuit to +12 volts.
NOTESSpecial notes: If fault DF024 with CO.0 or CC.1, the level 1 warning light illuminates
along with the message Faulty injection.
The fuel flow actuator is fully open, there is a clicking, and the engine is stopped
to prevent it from racing.
Check the connection and condition of the fuel flow actuator connector.
Repair if necessary.
Check the connection and condition of the computer 48-track brown connector B.
Repair if necessary.
Measure the resistance between tracks 1 and 2 of the flow actuator.
Replace the flow actuator if the resistance is not 5.3 W +
0.5 Ω at 20°C.
Check the insulation, continuity and the absence of interference resistance on the following connection:
Computer connector B track M4 Track 1 fuel flow actuator
Repair if necessary.
DDCR_V44_DF024P/DDCR_V48_DF024p
13B-58
AFTER REPAIRDeal with any faults declared by the diagnostic tool. Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V4 MR-372-J84-13B000$062.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
DF053
STOREDRAIL PRESSURE REGULATION FUNCTION
1.DEF: At minimum limit
2.DEF: At maximum limit
3.DEF: Below minimum threshold
4.DEF: Above maximum threshold
5.DEF: High flow current < minimum
6.DEF: High flow current > maximum
7.DEF: Low flow current < minimum
8.DEF: Low flow current > minimum
NOTESSpecial notes:
If DF053, the engine may stop, with the level 1 and 2 warning lights illuminated along
with the message Faulty injection.
Priority when dealing with a number of faults:
– DF007 Rail pressure sensor circuit,
– DF098. Fuel temperature sensor circuit.
Conditions for applying fault finding procedures to stored faults:
The fault is present with the engine running.
4.DEF
6.DEF
8.DEF
NOTESNone.
Check the connection and condition of the fuel flow actuator connector (brown IMV connector on the pump).
Repair if necessary.
Measure the resistance between tracks 1 and 2 of the flow actuator.
Replace the flow actuator if the resistance is not 5.3 Ω +
0.5 Ω at 20°C.
Check the connection and condition of the computer 48-track brown connector B.
Repair if necessary.
Check the insulation, continuity, and the absence of interference resistance on the following connection:
Computer connector B track M4 Track 1 fuel flow actuator
Repair if necessary.
Check that there is fuel present in the tank and that it is correct. Run Test 13 Diesel fuel conformity check.
Run Test 1 Low pressure circuit check.
DDCR_V44_DF053M/DDCR_V48_DF053M
DIESEL INJECTION
Fault finding – Interpretation of faults
13B-81
AFTER REPAIRDeal with any faults declared by the diagnostic tool. Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V4 MR-372-J84-13B000$062.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DDCR INJECTION
Vdiag No.: 44, 48
DF130
STOREDFLOW CAPACITY FUNCTION
NOTESSpecial notes:
If DF130, the engine may stop with the level 1 and 2 warning lights illuminated along
with the message Faulty injection.
Conditions for applying fault finding procedures to stored faults:
The fault is present with the engine running.
Check the connection and condition of the of the fuel flow actuator connector (IMV), and repair it if necessary.
Measure the resistance between tracks 1 and 2 of the flow actuator.
Replace the flow actuator if the resistance is not 5.3 Ω ± 0.5 Ω at 20°C.
Check the connection and condition of the computer 48-track brown connector B.
Repair if necessary.
Check the insulation, continuity and the absence of interference resistance on the following connection:
Computer connector B track M4 track 1 fuel flow actuator
Repair if necessary.
Check that there is fuel present in the tank and that it is correct. Run Test 13 Diesel fuel conformity check.
Run Test 1 Low pressure circuit check.
Run Test 6 High pressure system check.
Repair if necessary.
DDCR_V44_DF130M/DDCR_V48_DF130M
13B-152V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
IMV = fuel flow actuator
TEST 6 High pressure system check
NOTESSpecial note:
Certain faults make it impossible to carry out this test - deal with these first.
IMPORTANT: It is pointless and dangerous to engage the starter motor for more
than 5 seconds.
Preliminary Checks:
– Check for the presence of fuel
– Check that there is no air in the low pressure circuit. Run TEST 1: Low pressure circuit check.
– Ensure that the correct fuel is being used. Run TEST 13 Diesel fuel conformity check.
It is possible to check the high pressure supply pump capacity by carrying out the following procedure:
–With the ignition off, disconnect the low pressure actuator from the pump (IMV brown connector) and connect
a test IMV or the MOT. 1711 adapter.
– Electrically disconnect the four injectors.
– Switch on the ignition, connect the diagnostic tool and re-establish dialogue with the injection system.
– Go to the Main computer statuses and parameters screen.
– Run the test cold, PR064 Coolant temperature < 30°C or equal to the ambient temperature.
– Engage the starter for 5 seconds.
– Read the rail pressure maximum value (PR038) during the test on the diagnostic tool.
Is the rail pressure greater than 1050 bar?
A
NO
B
YES
DDCR_V44_TEST06/DDCR_V48_TEST06