PREVOST X3-45 2016, Maintenance Manual

Page: 121 / 459

Section 06: ELECTRICAL
PA1593
25
Problem/Symptom Probable Causes Actions
Response ModA54, Active” indicates
a power problem on the module. (A
CAN network problem would show
the same message but doesn't
produce this symptom).
3. Check / reset circuit breaker CB5
4. Check / replace fuse F67 , F68
5. Probe gray connector on module to
see if it is powered.
HVAC condenser fans not
functioning in speed 1 Module A54 is not powered
or is faulty
1. Check the Diagnostics menu of
Driver Information Display (DID).
Select
Fault Diagnostics and
Electrical System . The message “No
Response ModA54, Active” indicates
a power problem on the module. (A
CAN network problem would show
the same message but doesn't
produce this symptom).
2. Check / reset circuit breaker CB5
3. Check / replace fuse F67 , F68
4. Probe gray connector on module to
see if it is powered.
Fire alarm telltale light
and audible alarm always
ON and there is no fire or
high temperature in the
engine compartment Short-circuited fire sensor or
defective sensor Prior to start the vehicle, cycle the ignition
key to the ON position, OFF position and
then ON position again and then start the
vehicle. This will deactivate the fire alarm
function. This has to be repeated each
time the vehicle is re-started
The vehicle is parked and
the electrical horn is acti-
vated to indicate a fire in
the engine compartment
but there is no fire Short-circuited fire sensor or
defective sensor Cycle the ignition switch between the ON
and OFF position twice within 3 seconds.
This will deactivate the fire alarm function.
This has to be repeated each time the
vehicle is parked
A single light, a group of
LED lights or another
function of the vehicle is
not functioning The multiplex outputs are
protected in current by an
internal “soft-fuse”. When an
output is shorted, it turns
OFF and stays OFF until the
"soft-fuse" is reset Turn the ignition switch to the OFF
position and turn to the ON position again.
This resets all "soft –fuses"
No backlighting in the
instrument cluster Circuit breaker CB10 is
tripped or fuse F20 blown Check / reset circuit breaker CB10
Check / replace fuse F20