Spicer TPCS Troubleshooting Guide: Older Systems (ECU's w_Dual Connectors) - Manual (Page 42)

42
Troubleshooting
Air Pressure Check
Note that the Tire Pressure Control System is not continuously
pressurized; pressure checks occur on a periodic basis. During tire
pressure checks, the system delivers compressed air to each channel
for approxi mately two seconds while monitoring the pressure in that
channel.
Code Description
Code 7P! displays if system air pressure is inadequate to perform a tire
pressure check.
Code 7P! displays when either the pressure switch will not close or
the wet tank pressure is too low. The components that can cause the
pressure switch to remain open include:
• Compressor governor cut­out set too low
• Air dryer needs service
• Pressure switch unplugged
• Faulty pressure switch
• Faulty compressor
• Open or broken line from wet tank to Pneu matic Control Unit
• Crimped or plugged line from wet tank to
• Pneumatic Control Unit
• Faulty Electronic Control Unit.
To correctly diagnose the faulty component, connect the Diagnostic
Tool (see Section 5 for test equipment and descriptions) and follow the
procedure in the 7P! troubleshooting tree.
See “Troubleshooting Tips” on page 20 for general guidelines on system
diagnostics.
Code:
7P!
Type:
Inadequate Air Pressure