13B - 14
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
c) Warning light management
Instrument panel display
The computer manages the data display on the instrument panel relating to engine operation. This involves
5 functions:
– 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.
For the Vdiag 44 and 48, it only lights up when the engine is running.
In Vdiag 4C, this warning light comes on if the system has one or more OBD faults.
13B - 16
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
3. Conditions for clearing an OBD fault
An OBD fault is cleared in several steps.
The fault present in the diagnostic tool is not stored (following repair) until after 3 trips with the vehicle.
The OBD warning light will only light up after these 3 driving cycles.
The warning light coming on does not always mean that there is a fault on the system.
In order that the OBD fault and the display parameters are cleared from the computer, the system goes
through 40 engine heating cycles.
An engine heating cycle is a driving cycle during which:
–the engine coolant temperature reaches at least 71.1 °C,
–the engine coolant temperature varies by 22.2 °C in relation to the engine starting temperature.
If one of these conditions is not fulfilled, the OBD fault will still be present or stored in the injection
computer.
