Checking For Open-Circuits

Fig 1: Checking Traffic Load On CAN Cables

Courtesy of VOLVO CARS CORPORATION

Ring break diagnostic 

A ring break diagnostic should be run to determine whether the fault has occurred.

To carry out a full ring break diagnostic of the MOST system, proceed as follows:

1. Switch off the ignition and remove the key
2. Connect separate external voltage feed to the communication tool.
3. Disconnect the battery negative lead. See BATTERY, DISCONNECTING
4. Wait 1 minute.
5. Ignition switch position II.
6. Connect the battery negative terminal.
7. Wait at least 30 seconds after switching on the ignition before reading off the position of the open-circuit.

Other information: 

• For information about fuses, see the appropriate service information.
• For information on battery location:BATTERY, REPLACING

• Continue 

  Refer to READING OFF THE POSITION OF THE OPEN-CIRCUIT