Spicer TPCS (Tire Pressure Control System) Driver Instructions - Manual (Page 4)

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System Maintenance
The Dana TPCS requires a constant supply of clean dry air. An adequately sized and maintained
air dryer is critical for continued proper operation of the Tire Pressure Control System. Even
though the air dryer may be working properly, moisture can accumulate in the wet tank during
normal operation due to the increase in air consumption. It is important to drain the wet tank
daily. Draining the wet tank completely (to 0 pressure) when the truck is not in use will help keep
moisture under control.
NOTE: System components that malfunction due to inadequate air quality (contamination) are
not covered by warranty.
Components
The following describes each component of Dana’s TPCS:
Wheel Valve (WV)
All axles controlled by the TPCS incorporate a Wheel Valve (WV) at each wheel end. Dual wheels
are typically connected to one WV at the outer wheel to provide tire pressure balance. When the
system is idle, the WV isolates the tire(s) from the system, thereby extending seal life since the
seals are not under constant pressure. The WV also ensures fail safe operation should the sys-
tem become disabled or inoperable. The WV provides for inflation of the tires from the vehicle
air supply via the pneumatic controller, and deflation of the tires upon system demand. In addi-
tion, a standard tank valve is included for manual inflation/deflation/pressure checking.
Electronic Control Unit (ECU)
The Electronic Control Unit (ECU) is the control center for the entire TPCS. The ECU receives
commands from the driver through the Operator Control Panel (OCP) and transmits and moni-
tors appropriate signals throughout the system. The ECU is typically mounted in the cab behind
the passenger seat near the Pneumatic Control Unit (PCU).
Operator Control Panel (OCP)
By using the Operator Control Panel (OCP) keys, the operator selects tire pressures for the con-
ditions encountered. The panel also displays such system parameters as current tire pressures,
selected modes, and system status. The OCP is mounted in the cab within view and reach of the
driver.
Pneumatic Control Unit (PCU)
The Pneumatic Control Unit (PCU) is a solenoid controlled manifold that receives commands
from the Electronic Control Unit (ECU) and controls the air system. It also contains the PCU
Sensor which transmits the pressure readings to the ECU. The PCU delivers the proper control
signal to the appropriate channel (steer/drive/trailer).