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).
A list of the control modules included in the MOST network for the vehicle in question is presented together with the result of the ring break diagnosis.
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 diagnosis detects a break in communication on the MOST network the result will be a break position.
- If there is no fault in the MOST network the result will be OK.
- 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 always counts backwards, irrespective of which, or how many control modules, are installed in the vehicle. 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:
- The first open-circuit position corresponds to 0. This means that the open-circuit is in the Integrated Audio Module (IAM) or in the cable between the Integrated Audio Module (IAM) and the infotainment control module (ICM).
- If the position is 1, go one step backwards in the chain. 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.NOTE:
The Phone module (PHM) is not standard and if one is not installed open-circuit position 1 Global positioning system module (GPS) applies.
Other information
- For information on the location and arrangement of the MOST control modules:LOCATION OF COMPONENTS
- Infotainment Control Module (ICM).
Refer to CHECKING CABLES AND COMPONENTS, INFOTAINMENT CONTROL MODULE (ICM)
- Multimedia module (MMM).
Refer to CHECKING CABLES AND COMPONENTS, MULTIMEDIA MODULE (MMM)
- Audio Control Module (AUD).
Refer to CHECKING CABLE AND COMPONENT AUD
- Subwoofer Module (SUB)
Refer to CHECKING CABLE AND COMPONENT SUB
- Traffic message channel module (TMC).
Refer to CHECKING CABLE AND COMPONENT TMC
- Global positioning system module (GPS).
Refer to CHECKING CABLE AND COMPONENT GPS
- Phone module (PHM)
Refer to CHECKING CABLE AND COMPONENT PHM
- Integrated audio module (IAM).
Refer to CHECKING CABLES AND COMPONENTS, INTEGRATED AUDIO MODULE (IAM)
- The result from the ring break diagnostic indicates that the MOST network is OK.
Refer to CHECKING CABLE AND COMPONENT
The result from the ring break diagnostic is POOR.