Blue Bird VISION 2011, Driver'S Handbook Manual

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r o u t i n e o p e r a t i o n
deF. DEF is carried on board the bus as a water solution in a 15 gallon storage tank.
The storage tank is sized to minimize operator filling, but within packaging and
weight constraints of the vehicle. The storage tank and DEF dosing system is pro-
tected from freezing since the DEF-solution solidifies at approximately 11°F (-12°C).
The SCR system consumes DEF at a rate of approximately 2% of the amount of fuel
used, depending on bus operation. Therefore a 15 gal tank of DEF will treat approxi-
mately 750 gallons of diesel fuel.
The DEF tank level indicator can be found in quadrant 3 of the message display
center located in the instrument cluster. This display provides a constant reading in-
dicating the percent of DEF in the tank. If a problem is identified with the amount
of fluid or the quality of the DEF a priority message will appear in quadrant 1 of the
message display center indicating the fault.
Keeping adequate levels of DEF in the tank is crucial to the operation of the SCR
system. When low levels in the DEF tank are indicated, refill the tank using only ap-
proved DEF solution. The DEF has its own tank and fill port with a blue cap. You will
notice the fill port is smaller than the diesel fuel port. This is to prevent putting diesel
fuel into the DEF tank. Conversely, care should be given not to put DEF in the diesel
fuel tank. Read all decals carefully before refilling.
Refer to Blue Bird and Cummins Service Manuals for detailed description of the
aftertreatment system.
deF levels of Priority notification
A system of driver alerts keeps the driver informed of when the DEF is in need of
service. When fluid is low or contaminated, several levels of alerts occur in sequence,
each indicating a more imperative warning. When priority warnings occur, they will
appear in Quad 1 of the Message Display in lieu of the odometer reading while Quad 3
indicates fluid level in the DEF tank at all times. The notifications are as shown below.
deF level 1. When the DEF level reaches 10% in the tank, a deF leVel loW warning
will appear in Quad 1 of the Message Display at which point the amber icon will
appear in the lower left warning bank. This warning is accompanied with a single
beep.
deF level 2. When the DEF level reaches 5% in the tank, a deF leVel criTicAl warn-
ing will appear in Quad 1 of the Message Display, this DEF LEVEL CRITICAL warning
display will flash from positive to negative (
DEF LEVEL I CRITICAL
) and the amber
icon will remain in the lower left warning bank. This warning is accompanied
with repeating beeps.
deF level 3. When the DEF level reaches 2.5% in the tank, a deF leVel derATe
warning will appear in Quad 1 of the Message Display, this DEF LEVEL DERATE warn-
ing display will flash from positive to negative (
DEF LEVEL I DERATE ). The amber
icon will commence flashing in the lower left warning bank and an addtional
amber icon will appear. At this point a 25% engine torque derating will occur.
DEF Fill located to the left of the entrance door.
DEF Fill Door
Diesel Fill