Ring Break Test

If there is a break in the ring (a defect between two control modules) the following fault patterns may occur:

• Transmit diode of the transmitting control module defective
• Power supply of the transmitting control module defective
• Internal control module fault of the transmitting control module
• Receiver diode of the receiving control module defective
• Power supply of the receiving control module defective
• Internal control module fault of the receiving control module
• Optical wave guide between transmitting and receiving control module defective

These faults may occur alone or in combination. To diagnose a ring break, the first step is to locate the two control modules between which the transmission failure has occurred.

This is accomplished with the ring break diagnostic function. Once the two control modules have been identified and the diagnostics have been performed, remember to check the power supply and ground circuit of both modules before condemning a module.

Testing of the transmit/receive diodes will be possible using the OPPS tester.