Pierce Enforcer, Operator'S Manual

Page: 118 / 196

OPERATION
5-56 / Driving the Vehicle
© 2018 Pierce Manufacturing Inc. All Rights Reserved.
temperatures, the extra heat load created by the retarder may exceed the rate at which the cooling system can
dissipate the transmission fluid heat load (at the shell and tube cooler) or the total heat load (at the radiator).
The
vehicle operator must observe the transmission temperature gauge & warning lights and reduce retarder
use if the transmission fluid temperature climbs too high.
When the cooling system capacity is exceeded, the transmission ECU will begin to cut back on the retardation output
to limit the degree of overheating, but not before the system temperatures have peaked beyond the normal operating
range. The warning light in the center of the instrument panel will illuminate and an alarm will sound when the
transmission output temperature exceeds 330°F, or if the transmission sump temperature exceeds 250°F. A warning
light adjacent to the transmission temperature gauge will illuminate and an alarm will sound if the gauge reading
exceeds 335°F. This provides a redundant warning to the operator that the critical temperatures have been
exceeded.
If the transmission high temperature warning light is illuminated, the transmission ECU will change the shift
sequence to hold the transmission in gear longer, effectively increasing the rpm of the engine. This increases the
speed of the cooling fan and water pump, which will increase the heat transfer rate of the cooling system and thereby
hasten the return of the transmission sump temperature to within the normal operating range.
Operation in High Ambient Temperature Conditions
The influence of retarder use on the cooling system temperatures will vary with the retarder capacity and the control
system options. The higher capacity settings produce higher amounts of heat. Control systems that apply 50 to 100
percent of the retarder as the throttle pedal is released produce the heaviest heat load. Frequent cycling on and off
the throttle pedal builds up heat rapidly even though the situation may not require braking effort. If constant use of
the retarder produces frequent overheat situations, consult your Pierce Dealer regarding a change to the control
system or capacity setting that will better suit your duty cycle and environmental conditions.
5-30. Stability Control (Optional)
5-30.1 Safe Vehicle Operation
When operating your vehicle, always use safe driving techniques. The driver is ALWAYS the most important part of
a safe vehicle operation.
5-30.2 Roll Stability Control (RSC)
Roll Stability Control (RSC) is an Anti-Lock Braking System (ABS) based system that senses when impending
rollover conditions occur, and if detected, intervenes in the operation of the truck by automatically reducing the
vehicle speed. All measuring and processing needed to calculate, and continuously update, the rollover risk is done
within the ABS Electronic Control Unit (ECU).
RSC is automatic. It becomes active when the ECU senses lateral acceleration that exceeds thresholds. It then
attempts to quickly reduce vehicle speed until the lateral acceleration falls below the determined threshold.
Note that RSC and ESC systems cannot prevent accidents and/or loss of control of the vehicle. RSC
and ESC systems are not a reason to take unnecessary risks. A driver can still exceed the physical
limitations of the system with either excess speed and/or extreme cornering, causing a loss of
directional control or roll over. Training is recommended when using either system.