Spicer CTIS (Central Tire Inflation System) Troubleshooting Guide - Manual (Page 50)

47
Service Codes
DDM – Dashes "--" (Code 75)
Type: Display Control Communications
Code Description
Code 75 indicates a communication problem between the
Electronic Control Unit (ECU) and the Driver Display Module.
All of the troubleshooting steps for code 75 involve checking
the condition of Electronic Control Unit and DDM circuits. If
no circuit problems are found, code 75 indicates either a
faulty DDM or a faulty Electronic Control Unit.
See "Troubleshooting Tips" for general guidelines on system
diagnostics.
System Mode Condition Possible Causes
(Listed in Likely Order of Occurrence)
Inflate Only Blank Display • No power to DDM
• No ground connection to DDM
• System voltage out of range (9-32 volts DC)
Inflate Only DDM displays dash dash
(nothing else on display) • No power or ground to ECU
• DDM to ECU wires open
• DDM to ECU wires shorted to ground
• DDM to ECU wires shorted to power
• DDM to ECU wires shorted together
• Faulty Driver Display Module
• Faulty Electronic Control Unit
ECU Harness Connector
6
7
8
9
10
3
2
1
4
5
DDM Display Harness Connector
A B C D E
A B C D E
A B C D E
F G H J K 3
2
1
F G H J K
F G H J K