13B-2V1 MR-376-X76-13B000$010.mif
13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
1. SCOPE OF THIS DOCUMENT
This document presents the fault finding method applicable to all computers with the following specifications:
2. PREREQUISITES FOR FAULT FINDING
Documentation type:
Fault finding procedure (this manual):
– Assisted fault finding (integrated into the diagnostic tool), Dialogys.
Wiring Diagrams:
– Visu-Schéma (CD-ROM),
Type of diagnostic tools:
–CLIP + sensor
Special tooling required:
3. REMINDERS
Procedure
To run fault finding on the vehicle computers, switch on the ignition.
Depending on the type of vehicle equipment, proceed as follows:
To cut off the + after ignition feed, proceed as follows:
*VLL — Very Long LifeVehicles: LOGAN/SANDERO/THALIA 2/SYMBOL 2/
DUSTER/KANGOO VLL*
Engines: K9K 714, 718, 740, 790, 792, 794, 796, 880,
890.
Function concerned: K9 DELPHI
(DCM 1.2) COMMON RAIL direct diesel injectionName of computer: DCM 1.2 injection
Program No.: 4C
Vdiag No.: 08
Special tooling required
Diagnostic tool
Multimeter
Elé. 1590112-track computer bornier
Elé. 1681Universal bornier
Mot. 1711Injector flow measuring kit
For vehicles with key/radiofrequency remote control unit,
switch on the ignition with the key.
For vehicles with key/radiofrequency remote control unit,
switch off the ignition with the key.
DCM1.2_V08_PRELI
DIESEL INJECTION
Fault finding – Introduction
13B-3V1 MR-376-X76-13B000$010.mif
DIESEL INJECTION
Fault finding – Introduction13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
Faults
Faults are declared either present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but have not been diagnosed within the current context).
The present or stored status of the faults should be taken into consideration when the diagnostic tool is used after
the + after ignition feed has been activated (without any of the system components being activated).
For a present fault, apply the procedure described in the Interpretation of faults section.
For a stored fault, note the faults displayed and apply the Notes section.
If the fault is confirmed when the instructions are applied, the fault is present. Deal with the fault.
If the fault is not confirmed, check:
– the electrical lines which correspond to the fault,
– the connectors on these lines (corrosion, bent pins, etc.),
– the resistance of the faulty component,
– the condition of the wires (melted or cut insulation, wear).
Conformity check
The purpose of the conformity check is to check data that does not produce a fault on the diagnostic tool when the
data is inconsistent. Therefore, this stage is used to:
– carry out fault finding on faults that do not have a fault display, and which may correspond to a customer complaint,
– check that the system is operating correctly and that there is no risk of a fault recurring after repair.
This section gives the fault finding procedures for statuses and parameters and the conditions for checking them.
If a status is not behaving normally or a parameter is outside permitted tolerance values, you should consult the
corresponding fault finding page.
Customer complaints - Fault finding chart
If the test with the diagnostic tool is OK but the customer complaint is still present, the fault should be dealt with by
customer complaints.
A synopsis of the general procedure to follow is provided on the following page in the form of a flow chart.
13B-11V1 MR-376-X76-13B000$030.mif
DIESEL INJECTION
Fault finding – System operation13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
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 version).
– Checking the pilot quantity by measuring deviation and dispersion.
By changing both the injection duration and advance, the quantity of fuel injected and the mixture's moment of
ignition can be readjusted.
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 emission control 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 offset this
disadvantage, the quantity of fuel injected must be increased, which means increased pressure (and more holes in
the injector nozzles).
For the DCM 1.2 injection system, the pressure reaches 1400 bar - 1600 bar in the rail and must be constantly
regulated. The measuring circuit comprises 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 fuel flow actuator (IMV) and the discharge pressure is controlled by the
injector valves. This compensates for pressure drops. The flow actuator enables the high pressure pump to supply
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 in amplitude not to open the injector (and pass through the return circuit from the injectors),
– long enough in time 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 fuel flow actuator control,
the rail pressure is limited by a discharge valve fitted on the pump.
New pump chamber filling procedure (pump boosting)
The pump lubrication goes through a booster cycle during which the pump is filled and pressurised before
"transferring" the diesel fuel to the rail.
This lubrication goes through programming called "filling the new pump chamber", which prohibits starting for
approximately 10 seconds (the time required to fill the pump and to start if the key is released before the end of this
"first starting" phase). Power latch is not necessary before attempting to start the vehicle again.
This procedure runs when a computer is replaced if the parameters relating to the rail pressure have not been
copied into the new computer, or otherwise, after reprogramming of the injection computer.
13B-13V1 MR-376-X76-13B000$030.mif
DIESEL INJECTION
Fault finding – System operation13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
Function: Air flow management
EGR valve control
The EGR system (Exhaust gas recirculation) comprises a proportional EGR valve, with a built-in valve position
feedback potentiometer. The EGR valve position is controlled by the potentiometer in a closed loop and/or by
changes in the estimated air flow.
Special feature of the K9K796 Euro 2 engine (Indonesia): The EGR solenoid valve is present on the vehicle, but not
used. It always remains closed. It must not be replaced on this vehicle (unless there is a mechanical fault).
Calculating the air flow
K9K 790 and 794 engines are not fitted with an air flowmeter. Instead, the amount of fresh inlet air is evaluated
based on the values supplied by the surrounding systems.
The (theoretical) air load is calculated using a model with various calculation parameters, which are:
– the inlet air temperature measured by a sensor located after the turbocharger and/or after the exchanger (if fitted),
– the turbocharging pressure,
– the atmospheric pressure (external air),
– the EGR valve position,
– the fuel flow,
– the engine speed.
The atmospheric pressure sensor is optional. If fitted, it sends back a signal relating to the atmospheric pressure to
an analogue port on the micro-controller. If not, atmospheric pressure is recovered based on the turbocharger
pressure and the engine field.
For K9K 792 and 796 engines, the flow of fresh air entering the engine is measured by a hot-wire ratiometric sensor.
This flowmeter is used to manage the amount of exhaust gas to be recirculated to ensure optimum recirculation
rates. A fresh air temperature sensor is integrated into the flowmeter. Air flow measurement allows closed-loop
control via the EGR valve.
Turbocharger control
K9K 796 engine:
The turbocharging system is made up of a solenoid valve which is used to control the wastegate to adjust the
absolute pressure of the inlet circuit.
K9K 790, 792, 794 engines:
The turbocharger system is controlled by the inlet pressure and does not need to be controlled by the computer.
Pre-postheating actuation
Pre-postheating actuation consists of controlling the heater plugs and the preheating warning light on the instrument
panel. The heater plugs are activated by a preheating unit (controlled by the injection computer), and the power is
supplied by the battery. After the ignition is switched on a preheating delay is activated. The indicator light comes on
for the activation period which is dependent on the battery voltage, atmospheric pressure and coolant temperature.
If the temperature is below a certain threshold, a postheating function can be used to improve the combustion
stability, and consequently engine operation (reducing unburnt particles and pollutant emissions).
13B-15V1 MR-376-X76-13B000$030.mif
DIESEL INJECTION
Fault finding – System operation13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
Instrument panel display
The computer manages the data display on the instrument panel relating to engine operation.
There are six functions concerned:
–the On board diagnostics MIL (Malfunction Indicator Lamp),
– pre-postheating,
– the coolant temperature,
– engine problems; Level 1 (non-critical fault) and Level 2 (emergency stop).
– detection of water in the fuel (depending on instrument panel).
These six functions are represented using four indicator lights.
Pre-postheating and electronic fault warning light (Level 1)
This light is used to indicate that the heater plugs are preheating and as a system fault indicator light:
– Continuously illuminated during + after ignition feed: indicates preheating of the heater plugs.
– Flashing after preheating and an automatic 3-second stop indicates a Level 1 fault (the function is not working
optimally and safety levels are reduced). The user must carry out repairs as soon as possible).
Engine coolant temperature warning light (Level 2)
This indicator light is used both as an in-operation indicator light and as a system fault warning light. It illuminates for
3 seconds when the power is switched on (automatic test procedure).
Continuously illuminated during + after ignition feed: indicates engine overheating or a Level 2 fault.
OBD warning light
This warning light is used to alert the driver of any injection faults that could lead to excessive pollution, or if the OBD
system has been deactivated.
The injection computer requests illumination of the OBD warning light for a present fault only after three successive
driving cycles.
The 3 second visual inspection when the ignition is switched on (automatic test procedure managed by the
instrument panel) is carried out by the injection computer.
13B-18V1 MR-376-X76-13B000$040.mif
DIESEL INJECTION
Fault finding – Replacement of components13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
After the computer has been programmed:
– Switch off the ignition.
– Switch on the ignition again and use the diagnostic tool to carry out the following steps:
– Use command SC001 Write saved data to restore the C2I and the engine adaptive programming.
– Run command VP010 Write VIN.
– Run command AC028 Static test.
– Run command AC154 Low speed fan assembly to test the operation of the 1st speed fan assembly.
– Run command AC153 High speed fan assembly to test the operation of the 2nd speed fan assembly.
– Run command AC250 Heating resistor 1 relay to test the operation of passenger compartment heating resistor 1.
– Run command AC251 Heating resistor 2 relay to test the operation of passenger compartment heating resistor 2.
– Run command AC100 Stop electrical consumer inhibition.
– Run command AC212 Fill new pump chamber.
– Run the starter motor without releasing the key until the engine starts (the pump reprime time until the engine starts
can be up to 20 seconds).
– After the engine has started, refer to ET637 Fill new pump chamber and check that it is Done; if not, repeat the
starting procedure.
–Stop the engine, switch off the ignition (to initialise the computer) and wait 30 seconds.
– After injection system programming, stored faults may appear in other computers.
– If DF1083 Water in diesel fuel warning light circuit appears in the injection computer: on a vehicle fitted with
a water in diesel fuel warning light, perform the fault finding operations described in DF1083 then run command
AC028 Static test; on other vehicles, do not deal with the fault.
– Clear the computer memory RZ001 Fault memory.
IMPORTANT
AFTER A (RE)PROGRAMMING OPERATION, DO NOT DISCONNECT THE BATTERY FOR AT LEAST
30 MINUTES (to carry out other work on the vehicle).
Note:
If commands SC003 Save computer data and SC001 Write saved data have been lost or do not work, after
programming the computer, enter the C2I for each injector manually by reading the C2I on each injector (see
Replacing the injectors).
13B-19V1 MR-376-X76-13B000$040.mif
DIESEL INJECTION
Fault finding – Replacement of components13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
REPLACING THE INJECTORS
The system can be configured with the diagnostic socket using the diagnostic tool.
The C2I parameters must be replaced after replacing an injector/injectors.
To do this, enter the C2I again into the injection computer using the following commands:
- VP001 Cylinder 1 injector for the cylinder 1 injector (cylinder on flywheel end),
- VP002 Cylinder 2 injector for the cylinder 2 injector,
- VP003 Cylinder 3 injector for the cylinder 3 injector,
- VP004 Cylinder 4 injector for the cylinder 4 injector.
It is also possible to enter all four C2I using command SC002 Enter injector codes.
REPLACING THE HIGH PRESSURE PUMP
PROCEDURE
– Switch on the ignition and use the diagnostic tool to re-establish dialogue with the injection computer.
– Use command AC212 New pump chamber filling.
– Operate the starter (Important: starting the engine may take 20 seconds due to the time taken to reprime the
pump).
– After the engine has started, refer to ET637 Fill new pump chamber and check that it is Done; if not, repeat the
starting procedure. Note:
C2I (individual injector correction) is a calibration carried out in the factory on each injector to adjust the flow
of each injector precisely.
The correction values are written on a label affixed to each injector, then entered in the computer which can then
actuate each injector by taking account of their manufacturing variations.
Only after simultaneously replacing at least three injectors, reset the injector adaptives, using command RZ004
Pressure regulation adaptives.
IMPORTANT
When reprogramming the computer, only carry out the following procedure after running command AC028
Static test (see Computer reprogramming operation).
13B-20V1 MR-376-X76-13B000$040.mif
DIESEL INJECTION
Fault finding – Replacement of components13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
REPLACING THE EGR VALVE
If the EGR valve is replaced, program the new valve's offset position.
Switch on the ignition and use the diagnostic tool to carry out the following:
– run command RZ002 EGR adaptives to clear the old offset using the EGR programming deletion procedure.
– Special feature of the K9K796 Euro 2 engine (Indonesia): The EGR solenoid valve is present on the vehicle, but
not used. It always remains closed. It must not be replaced on this vehicle (unless there is a mechanical fault).
IMPORTANT
Do not use this command if the valve is not new.