Obtaining A Break Position Reading
- Ignition on
Obtaining a reading of the ring break diagnosis result
Obtain a reading of the ring break diagnosis result using the VCT2000 (or appropriate scan tool). The script also presents a list of all control modules connected to the MOST network.
The following results can be obtained from a ring break diagnosis:
- If the fault occurs while the ring break diagnosis is running the result will be presented in the form of a break position.
- If the fault does not occur while the ring break diagnosis is running the result will be OK. In such case continue by selecting alternative 3 below.
- If the infotainment module (ICM) receives signals on the MOST network but cannot decode them because they are distorted or the light strength is too weak, the result will be POOR.
Determining the break position
The break position is counted backwards from the infotainment module (ICM) in the MOST network.
NOTE:The ring break diagnostic only counts backwards, irrespective of which or how many control modules are installed in the car. To determine the position of the open-circuit, check the list to, see which control modules are installed in that particular vehicle. Then count backwards following the determined order. The number of control modules can vary between 2 and 8.
Two examples are given in the following:
- First open circuit position is indicated by 4. This means that the open-circuit is in the Subwoofer module (SUB) or in the cable between the Remote Digital Audio Receiver (RDAR) and the Subwoofer module (SUB).
- First open circuit position is indicated by 2. This means that the open-circuit is in the Phone module (PHM), or in the cable between the Phone module (PHM) and the Integrated Audio Module (IAM). The open-circuit may be caused by the optical connector in the Integrated Audio Module (IAM) being damaged. This means that the Integrated Audio Module (IAM) does not interpret the incoming signal from the Phone module (PHM) correctly.
Select an alternative which includes the control module that is to be checked.
Alternative 1:
Refer to CHECKING CABLE AND COMPONENT
Accessory USB unit (AUU).
Phone module (PHM)
Bluetooth phone module (BPM).
Integrated audio module (IAM)
Subwoofer Module (SUB)
Alternative 2:
Refer to CHECKING CABLE AND COMPONENT
Audio module (AUD)
Remote Digital Audio Receiver (RDAR).
Multimedia module (MMM)
Infotainment control module (ICM)
Alternative 3:
Refer to CHECKING CABLE AND COMPONENT
The ring break diagnosis result shows that the MOST network is OK.
The ring break diagnosis result is POOR.
Other information