Selective catalytic reduction
emission-related faults. There is a delay
in the system which means that the MIL
symbol does not illuminate immediately
when the error occurs but can be
illuminated much later. In addition, and in
accordance with legal requirements, the
lamp is illuminated for a period after the
error has been rectified.
MIL symbol
Faults that are discovered are classified
according to how large an effect they
have on the exhaust gas cleaning.
A. Large effect
B. Medium effect
C. Smaller effect
Performance changes
Warnings about faults will be shown in
the driver information display. The
message will indicate the nature of the
fault. If the fault has not been rectified
then the performance of the bus will be
gradually reduced. The following occur:
1 Warning of pulling power reduction.
2 Engine pulling power is reduced by
25%.
3 Warning about speed limitation.
4 Speed limitation to 20 km/h.
Monitoring
The MIL symbol appears if a fault has
occurred. The flash pattern depends on
the category of the fault and whether it is
during driving or if the engine is turned
off.
While driving
If the MIL symbol illuminates, for the first
15 s or remains illuminated during
driving, a fault has occurred.
Contact your Volvo workshop.
Engine turned off
When the starter switch is in ignition
position and the engine is not running
the MIL symbol flashes. The flash
patterns advise on the status of the
system.
NOTE
The MIL symbol will also flash when
everything is working as it should be.
Flash patterns
Normal condition, no faults.
Normal condition, no faults. However,
certain tests could not be conducted
since conditions for testing have not
been fulfilled.
Other flash patterns
Other flash patterns indicate that the
exhaust gases do not fulfil the legal
requirement, or that the monitoring
system on-board diagnostic (OBD) is not
working as it should be. Contact a Volvo
workshop.
08
Fuel and emission control
129
To Next Page
