Reading Off The Position Of The Open-Circuit
- Ignition on.
Reading off the result from a ring break diagnostic
Click the VCT2000 (Volvo Scan Tool) symbol to read off the result of the ring break diagnostic.
The following results can be obtained from a ring break diagnosis:
- If the diagnostic detects a communication failure on the MOST network, the result will be the name of the control module positioned before the failure. The name of the control module, which has the relevant address, is also presented.
- The result will be OK if there is no fault on the MOST network.
- If the Infotainment control module (ICM) gets a signal on the MOST-net, but is unable to decode the signals due to the light intensity being too weak or the signals are too distorted, the result becomes poor signal .
- If all control modules on the MOST network believe that they are slave nodes the result is diag all units slave .
- If one or several control modules on the MOST-net consider themselves master nodes, the result becomes diagnosis multimaster .
If the result shows any of the three later alternatives, this must be verified by carrying out the entire test again. Then follow fault tracing for the relevant alternative.
Determining the position of the open-circuit
The Ringbreak diagnostic works so that after the control modules have been powered down and then restarted, each control module on the MOST-circuit sends its address to the Infotainment control module (ICM).
If the diagnostic detects a communication failure on the MOST network, the result will be the name of the control module positioned before the failure. The name of the control module, which has the relevant address, is also presented.
Select the relevant alternative .
Alternative 1
Infotainment Control Module (ICM).
Refer to CHECKING CABLES AND COMPONENTS, INFOTAINMENT CONTROL MODULE (ICM)
Alternative 2
Phone module (PHM)
Bluetooth phone module (BPM).
Audio Control Module (AUD).
Multimedia module (MMM).
Subwoofer Module (SUB)
Remote Digital Audio Receiver (RDAR).
Digital Audio Broadcast Module (DABM).
Integrated audio module (IAM).
Refer to NO COMMUNICATION
Alternative 3
The result from the ring break diagnostic indicates that the MOST network is OK.
The result from the ring break diagnostic displays a poor signal.
The result from the ring break-diagnosis shows diagnosis multimaster.
Refer to CHECKING THE CABLE AND COMPONENT
Alternative 4
The result from the ring break-diagnosis shows diagnosis all units slave.
Refer to CHECKING THE INFOTAINMENT CONTROL MODULE (ICM)