Ring Open-Circuit on O-Bus Detected

Ring Open-Circuit On O-Bus Detected







Fault symptom
The diagnostic tool shows "Ring open-circuit on O-bus detected".

Diagnostic help
- To localise the ring open-circuit, run diagnostics "Ring open-circuit position, O-bus" under the All/Bus menu and follow the instructions in the diagnostic tool.
- Communication with CIM is necessary for Tech 2 to be able to communicate with all systems.
- The Diagnostic instrument main menu "All systems/Read configuration" shows a list of those systems with which the vehicle in question was equipped before the fault was detected.
- The current status of each system is shown to the right.
- "OK" if control module communicates correctly.
- "MISSING" if control module is not on the bus.
- "ADDED" if the control module has not yet been added.
- "NOT EQUIPPED" indicates that the control module is not fitted to the vehicle.

NOTE: applies before reset of bus configuration.

Functions in the diagnostic tool related to the fault
- Read/Reset Bus Configuration
- Read/Clear Bus Off Counter
- Response Test

WARNING: The visible red light is of laser class 1. Do not look directly into the optical fibre or the control module connector at a close distance. If there is less than 20 mm distance between the eye and the light source, the eye may be injured.

Checking the wiring harness

IMPORTANT: Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.