Spicer CTIS (Central Tire Inflation System) Troubleshooting Guide - Manual (Page 4)

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General Information
Central Tire Inflation System (CTIS)
Spicer’s Central Tire Inflation System features driver control of
tire air pressure through:
• Simple push button operation.
• Electronic braking priority for air system.
• Vehicle speed sensing and response capability.
• Self-diagnostics.
• Optional independent front and rear operation.
• Optional load selection.
Key Features
Depressurized Control Lines
The only time the system is pressurized is when changing tire
pressures or during pressure checks. Wheel valves isolate the
tires from the rest of the system.
Electronic Braking Priority
A pressure switch, installed in the supply tank, controls the
CTIS and use of air. This optimizes and protects the brake
system’s primary tank pressures during system operation.
Self-Diagnostic and Auto Shut-Down
The Spicer CTIS provides self-diagnosis during operation. If
the system detects a problem, it will display a series of flash-
ing lights on the Electronic Control Unit (ECU) panel to alert
the driver. If necessary, it will close the wheel valves and shut
down.
Diagnostic Capability
The Spicer CTIS provides for easy troubleshooting using
PC-based or industry standard tools. Personal computer-
supported diagnostics improve troubleshooting and reduce
maintenance time. The diagnostics provide for manual control
of CTIS test sequences and gives historical and active service
code data.
Speed/Pressure Control and Warning
If truck speed exceeds the maximum allowable speed for a
given setting, a panel-mounted light is activated by CTIS to
warn the driver. If speed is not reduced, the system
automatically inflates the tires to the appropriate pressure.
Manual Tire Inflation/Deflation
A valve stem has been included on each wheel valve, and may
be used for manual inflation, deflation, or measurement of tire
pressures.
Run Flat Operation
The CTIS normally checks tire pressures at intervals of 15
minutes. If possible tire damage is detected, the system will
activate Auto RUN FLAT. RUN FLAT reduces the pressure
check interval to 15 seconds, helping to assure that the tire
will remain inflated despite minor tire damage.