freightliner M2 Plus 2023 Manual page 43

Normal pressure, with the engine running, is 100 to
120 psi (689 to 827 kPa) in both systems.
08/16/2019
Fig. 3.40, Analog Combined Application Air Pressure
Gauge - ICUC
NOTE: The low-air warning buzzer only works
when the park brake is released. The low-air
warning buzzer is silenced when the park brake
is set.
If air pressure drops below approximately 70 psi (483
kPa), a warning light illuminates and the driver
display shows a warning. A low-air warning buzzer
also sounds if the park brake is not set.
NOTE: If the pressure in both air systems drops
below 70 psi, the parking brakes will drag or
apply.
Speedometer
The U.S. version of the speedometer shown in
Fig. 3.41 registers speed in both miles per hour
(mph) and kilometers per hour (km/h), with mph in
larger numbers. The metric version of the
speedometer face reverses this arrangement, with
km/h in larger numbers.
08/16/2019
Fig. 3.41, Analog Speedometer - ICUC
f611779
Suspension Air Pressure Gauge
A suspension air pressure gauge registers the air
pressure applied to the vehicle air suspension. See
Fig. 3.42.
10/31/2016
Fig. 3.42, Suspension Air Pressure Gauge
Tachometer
The tachometer or rev counter indicates engine
speed in revolutions per minute (rpm) and serves as
a guide for shifting the transmission and keeping the
engine in the appropriate rpm range. The tachometer
has only one unit of measurement, 0-2500 rpm. For
low idle and rated rpm, consult your vehicle's engine
identification plate. See
Instruments
f611782
f611468
Fig. 3.43.
3.22