Auto Tech Line
WARNING LIGHT MANAGEMENT
Management of instrument panel warning lights according to the faults notified.
DTC Diagnostic tool title
Level 1 fault
Level 2 fault
warning light (Red
Faults are declared as 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 faults should be taken into consideration when the diagnostic tool is switched on
after the + after ignition feed (without any system components being active).
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 instructions in the Notes section.
If the fault is confirmed when the instructions in the Notes section are applied, the fault is present. Deal with the
If the fault is not confirmed, check:
– the electrical lines which correspond to the fault,
– the connectors for these lines (for oxidation, bent pins, etc.),
– the resistance of the component detected as faulty,
– the condition of the wires (melted or split insulation, wear).
The aim of the conformity check is to check statuses and parameters that do not produce a fault display on the
diagnostic tool when they are 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
– check that the system is operating correctly and that there is no risk of a fault recurring after repairs.
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 the permitted tolerance values, 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 processed by
Warning light management
Instrument panel display
The computer manages the data display on the instrument panel relating to engine operation. This involves
– the OBD warning light (European On Board Diagnostic),
– pre/postheating warning light,
– the coolant temperature warning light,
– the fault level 1 warning light (non-critical fault),
– the fault level 2 warning light (stop immediately).
These five functions are represented by 3 warning lights or messages sent by the trip computer.
Pre/postheating indicator light
This warning light is used both as an in operation indicator light and as a system fault indicator:
– continuously lit under + after ignition feed: indicates that the heater plugs are operating,
– continuously lit with injection faulty: indicates a level 1 fault (involves injection system operating in defect
mode. The user must carry out repairs as soon as possible).
Temperature/emergency stop warning light
This indicator light is used both as an in-operation indicator light and as a system fault warning light. It lights up for
3 seconds after the ignition is switched on (automatic test procedure managed by the instrument panel).
– continuously lit: indicates engine overheating (the driver remains free to stop the vehicle or not),
– continuously lit, with the Engine stop message: indicates a level 2 fault (In this case injection is
automatically shut off after a few seconds).
Excess pollution OBD orange warning light
An engine symbol lights up for approximately 3 seconds when the engine is switched on.
– Determines the value of injection pressure necessary for the engine to operate correctly and then controls the
– It checks that the pressure value is correct by analysing the value transmitted by the pressure sensor located on
– It determines the injection timing required to deliver the right quantity of diesel fuel and the moment when injection
– 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,
– fuel supply check (advance, flow and rail pressure),
– the fan assembly via the Protection and Switching Unit (centralised coolant temperature management
– the air conditioning (cold loop function),
– the cruise control/speed limiter function,
– the pre-postheating control.
– the 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 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.
a diesel filter,
– a high pressure pump with an integrated low pressure pump (transfer pump),
– a high pressure regulator mounted on the pump,
– an injection rail,
– a diesel fuel pressure sensor integrated into the rail,
– four solenoid injectors,
– a diesel fuel temperature sensor,
– a coolant temperature sensor,
– an upstream air temperature sensor,
– a cylinder reference sensor,
– an engine speed sensor,
– a turbocharging pressure sensor,
– an accelerator pedal potentiometer,
– an EGR solenoid valve,
– an atmospheric pressure sensor integrated into the injection computer,
– an air flow sensor,
– a turbocharging pressure limitation solenoid valve,
– a damper flap solenoid valve..
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 gang 1
DF009 2120 Pedal potentiometer circuit gang 2
DF010 0409 EGR position sensor circuit
DF014 0500 Vehicle speed signal 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 Preheating unit fault finding 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 supply voltage
DF049 0530 Refrigerant sensor circuit
DF050 0571 Brake switch circuit
DF051 0575 Cruise control/speed limiter function
DF052 0200 Injector control circuit
DF053 0089 Rail pressure regulation function
DF054 0033 Turbocharging solenoid valve control circuit (728, 729)
DF056 0100 Air flow sensor circuit (728, 729)
DF057 2264 Water in diesel fuel detector circuit
DF059 0301 Misfires in cylinder 1
DF060 0302 Misfires in cylinder 2
DF061 0303 Misfires in cylinder 3
DF062 0304 Misfires in cylinder 4
DF089 0235 Inlet manifold pressure sensor circuit
DF098 0180 Fuel temperature sensor circuit
DF107 0604 Computer memory
DF112 0340 Cylinder reference sensor circuit
DF113 0608 Sensor supply voltage
DF114 0400 EGR solenoid valve circuit
DF116 C001 Multiplex network
DF121 0325 Accelerometer circuit
DF122 0609 Supply voltage pedal potentiometer gang 2
DF130 0087 Flow capacity function
NO COMMUNICATION WITH THE COMPUTER ALP 1
STARTING FAULT OR STARTING IMPOSSIBLE ALP 2
INJECTION NOISE ALP 3
POOR PERFORMANCE ALP 4
IRREGULAR ENGINE OPERATION ALP 5
ROUGH IDLE ALP 6
OIL LEAKS FROM THE TURBOCHARGER ALP 7
TURBOCHARGER NOISE ALP 8
SMOKE FROM THE EXHAUST ALP
The OBD (On Board Diagnostic) system enables 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 operating cycles, and the following parameters will be saved in the calculator:
– engine load,
– vehicle speed,
– air temperature,
– coolant temperature,
– turbocharging pressure,
– rail pressure,
– air flow,
– vehicle mileage.
It allows the driver to know whether their 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:
– DF012 Sensor supply voltage no. 2.
– DF038 Computer.
– DF040 Cylinder 1 injector circuit.
– DF041 Cylinder 2 injector circuit.
– DF042 Cylinder 3 injector circuit.
– DF043 Cylinder 4 injector circuit.
– DF209 EGR valve position sensor circuit.
– DF272 EGR valve control circuit.
– DF621 EGR valve jammed open.
Some repair operations require programming to ensure that certain engine components function correctly.
Follow the programming procedures (described in the
EGR valve opening setpoint
PR006 Rail pressure regulator current
PR007 Rail pressure regulator current setpoint
PR008 Rail pressure setpoint
PR009 Turbocharging pressure setpoint
PR011 Turbocharging solenoid valve position correction
PR015 Engine torque
PR016 Alternator flow
PR017 Fuel flow
PR022 EGR valve position feedback loop difference
PR030 Accelerator pedal position
PR035 Atmospheric pressure
PR037 Refrigerant pressure
PR038 Rail pressure
PR041 Turbocharging pressure
PR046 EGR solenoid valve OCR
PR047 Turbocharging pressure OCR
PR048 Rail pressure regulation valve OCR
PR050 Damper flap OCR
PR051 EGR valve position feedback
PR053 Speed requested by air conditioning
PR055 Engine speed
PR059 Inlet air temperature
ET001 + After ignition computer feed
ET003 Engine immobiliser
ET004 Air conditioning authorisation
ET007 Preheating unit control
ET014 Check cooling fan 1
ET015 Check cooling fan 2
ET021 High speed fan assembly request
ET022 Low speed fan assembly request
ET035 Reverse gear signal
ET042 Cruise control/speed limiter
ET077 Impact detected
ET078 Air regulation
ET079 Air conditioning present
ET088 Compressor actuation request
ET104 Injector code use
ET111 RCH* number set
ET112 RCH* cut-off
ET233 Clutch pedal
ET341 Immobiliser code programmed
ET405 Clutch pedal switch
ET413 Cruise control/speed limiter function
ET415 Deactivation of cruise control/speed limiter
ET703 Cruise control/speed limiter buttons
ET704 Brake switch no. 1
ET705 Brake switch no. 2