13B-10V1 MR-376-X76-13B000$030.mif
13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
System outline
The DCM 1.2 injection system used on the K9K 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 takes place
when a current pulse is applied to the injector holders.
The amount injected is proportional to the rail pressure and the applied pulse length, and the start of injection is
synchronised with the start of the pulse.
The system includes two subsystems, which have different fuel pressure levels:
– the low pressure circuit contains the tank, the diesel fuel filter, the transfer pump and the injector holder return pipes,
– the high pressure circuit contains the high pressure pump, the rail, the injector holders and the high pressure pipes.
The injection system contains a number of sensors and 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 setting
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 charge (Flow and Pressure).
– Pressure in the rail.
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.
Each injector holder is controlled by an electrical current which is sent according to previously calculated data. The
system makes one or two injections (one pilot injection, one main injection).
The general principle is to calculate an overall injected flow, which is then divided into the main injection flow and a
pilot injection flow to promote correct combustion and help reduce pollutant emissions.
DIESEL INJECTION
Fault finding – System operation
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-28
AFTER REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$071.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF003
PRESENT
OR
STOREDATMOSPHERIC PRESSURE SENSOR CIRCUIT
CO.0: Open circuit or short circuit to earth
CC.1: Short circuit to +12 V
NOTESSpecial notes:
The atmospheric pressure sensor is built into the injection computer.
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
Look for any wiring harness damage and check the condition and connection of the injection computer connectors,
component code 120.
Check the connection and condition of the injection locking relay connector.
If the connectors are faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or Technical
Note 9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the connector, otherwise
replace the wiring.
Move the wiring harness between the injection computer and the battery, component code 107 to see if a change
of status occurs (Present Stored).
Look for any damage to the wiring and check the connection and condition of the battery and its connections.
If the connector is faulty and there is a repair procedure (see Technical Note 6015A (Renault) or Technical Note
9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the connector, otherwise replace
the wiring.
Measure the battery voltage when the ignition is switched on.
If the battery voltage is less than 11 V, recharge the battery (see Technical Note 6014A (Renault) or Technical
Note 9859A (Dacia), Checking the charging circuit).
Check the condition and connection of the battery terminals and posts.
DCM1.2_V08_DF003
13B-69
AFTER
REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$072.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF047
PRESENT
OR
STOREDCOMPUTER SUPPLY VOLTAGE
1.DEF: Above maximum threshold
2.DEF: Below minimum threshold
NOTESConditions for applying the fault finding procedure to a stored fault:
The fault is declared present with the engine running at over 1000 rpm.
Special notes:
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
Move the wiring harness between the injection computer, component code 120 and the battery, component code
107 to see if a change of status occurs (Present
Stored).
Look for any damage to the wiring harness and check the connection and condition of the battery and its
connections.
If the connectors are faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or Technical
Note 9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the connector, otherwise
replace the wiring.
Measure the battery voltage when the ignition is switched on.
If the battery voltage is less than 11 V, recharge the battery.
Check the condition and connection of the battery terminals and posts.
Check the charging circuit of the vehicle (see Technical Note 6014A (Renault) or Technical Note 9859A (Dacia),
Checking the charging circuit).
DCM1.2_V08_DF047
13B-86
AFTER
REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$072.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF089
PRESENT
OR
STOREDINLET MANIFOLD PRESSURE SENSOR CIRCUIT1.DEF: Permanent low level
2.DEF: Permanent high level
3.DEF: Below minimum threshold
4.DEF: Above maximum threshold
5.DEF: Inconsistency
6.DEF: At maximum stop
7.DEF: At minimum stop
NOTESPriority when dealing with a number of faults:
– DF113 Sensor supply voltage.
Special notes:
If fault DF089 is present, the engine speed is maintained at 1000 rpm, engine
performance is reduced to 75% and the level 1 warning light comes on.
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
1.DEF
2.DEF
3.DEF
4.DEF
NOTESNone.
Check the condition and connection of the turbocharging pressure sensor connector, component code 1071.
Check the condition of the injection computer connector, component code 120.
If the connectors are faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or Technical
Note 9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the connector, otherwise
replace the wiring.
Check for + 5 V on connection 3LQ of the turbocharging pressure sensor, component code 1071.
Check for earth on connection 3LN on the turbocharging pressure sensor, component code 1071.
If the connection(s) are faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or
Technical Note 9804A (Dacia), Repairing electrical wiring, Wiring: Precautions for repair), repair the wiring,
otherwise replace it.
DCM1.2_V08_DF089
13B-109
AFTER
REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$072.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF261
PRESENT
OR
STOREDTURBOCHARGER ACTUATOR CIRCUIT
CC.1: Short circuit to + 12 V
CO.0: Open circuit or short circuit to earth
NOTESSpecial notes:
If fault DF261 is present, the air flow regulation is switched off, the EGR valve is closed,
and the turbocharging regulation is switched off.
Injection defective message displayed on the instrument panel and reduced
performance.
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
Run TEST 11 Air line at the turbocharger.
Run TEST 5 Inlet circuit check.
Run TEST 10 Turbocharger solenoid valve check.
Run Test 12 Turbocharger.
Check the inlet pressure signal, check the gear number when changing gear.
If the fault is still present, contact the Techline.
DCM1.2_V08_DF261
13B-110
AFTER
REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$072.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF427
PRESENT
OR
STOREDTURBO ACTUATOR CONTROL
1.DEF: At minimum stop
2.DEF: At maximum stop
NOTESSpecial notes:
If fault DF427 is present, the air flow regulation is switched off, the EGR valve is closed,
the turbocharging regulation is switched off and reduced performance.
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
Run TEST 11 Air line at the turbocharger.
Run TEST 5 Inlet circuit check.
Run TEST 10 Turbocharger solenoid valve check.
Run Test 12 Turbocharger.
Check the turbocharging pressure signal, check the gear number when changing gear.
If the fault is still present, contact the Techline.
DCM1.2_V08_DF427
13B-113
AFTER
REPAIRDeal with any faults declared by the diagnostic tool.
Clear the computer memory.
Carry out a road test followed by another check with the diagnostic tool.
V1 MR-376-X76-13B000$072.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DCM 1.2 Injection
Program no.: 4C
Vdiag No.: 08
DF532
PRESENT
OR
STOREDALTERNATOR CHARGE SIGNAL
1.DEF: Inconsistency
2.DEF: No signal
NOTESConditions for applying the fault finding procedure to a stored fault:
If the fault is declared present after the engine has been started.
Special notes:
Use bornier Elé. 1681 for any operations on the injection computer connectors.
Use the Wiring Diagrams Technical Note for Logan, Sandero, Duster, Thalia 2/
Symbol 2 or Kangoo VLL.
Check the condition of the alternator connector, component code 103.
Check the condition of the injection computer connector, component code 120.
If the connectors are faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or Technical
Note 9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the connector, otherwise
replace the wiring.
Check the continuity and the absence of interference resistance on the following connection:
●2K between components 120 and 103.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A (Renault) or Technical
Note 9804A (Dacia), Electrical wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise
replace it.
Check the charging circuit (see Technical Note 6014A (Renault) or Technical Note 9859A (Dacia), Checking
the charging circuit).
Carry out the necessary repairs.
If the fault is still present, contact the Techline.
DCM1.2_V08_DF532