PREVOST H3-45 VIP Owner's Manual page 219

Problem / Symptom
Evaporator fan not
functioning
HVAC condenser fans not
functioning in speed 1
Sound system not
functioning
Fire alarm telltale light and
audible alarm always ON
and there is no fire or high
temperature in the engine
compartment
Probable Causes
Circuit breaker CB3 tripped
Module AE54 is not powered or
is faulty
Module AE54 is not powered or
is faulty
Circuit breaker CB11 tripped
Short- circuited fire sensor or
defective sensor
PA-1638 Owner's Manual X3-45 VIP
Multiplex Troubleshooting B-7
Actions
1. Check circuit breaker CB3
2. Check relay R12
3. Check the DIAGNOSTICS menu of
Driver Information
Select VIEW ACTIVE FAULTS and
ELECTRICAL.
Response ModA54, Active" indicates a
power problem on the module. (A DL0
(BBUS MUX) network problem would
show the same message but doesn't
produce this symptom).
4. Check / reset circuit breaker CB5
5. Check / replace fuse F135
6. Probe gray connector on module to see
if it is powered.
1. Check the DIAGNOSTICS menu of
Driver Information
Select VIEW ACTIVE FAULTS and
ELECTRICAL.
Response ModA54, Active" indicates a
power problem on the module. (A DL0
(BBUS MUX) network problem would
show the same message but doesn't
produce this symptom).
2. Check / reset circuit breaker CB5
3. Check / replace fuse F135
4. Check / replace fuse F141-F144
5. Probe gray connector on module to see
if it is powered.
1. Check CB11
2. Check / replace fuse F148, F200
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
restarted.
Display (DID).
The message "No
Display (DID).
The message "No