Spicer TPCS Troubleshooting Guide: Older Systems (ECU's w_Dual Connectors) - Manual (Page 36)

36
Troubleshooting
Code Description
Code 3P! displays when the system is generating a vacuum at a time
when the Electronic Control Unit (ECU) is not requesting a vacuum.
Creating an unexpected vacuum is a highly unlikely event. If it should
occur, vacuum may cause a pressure drop in the wet tank.
The most likely cause of an unexpected vacuum is a faulty Pneumatic
Control Unit (PCU). Verify the problem before replacing the Pneumatic
Control Unit. See the procedure in the 3P! troubleshooting tree.
See “Troubleshooting Tips” on page 20 for general guide lines on system
diagnostics.
Code:
3P!
Type:
Vacuum Fault