Checking Cable And Component

If the result of the ring break diagnostic is POOR, the infotainment control module (ICM) is receiving a signal on the MOST network. However it is unable to decode the signals because the luminance of the signals is too weak or the signals are distorted.

If the result from the ring break diagnostic is OK, the fault is intermittent.

Fault-tracing using the ring break diagnostic assumes that the fault is permanent or active when the test is run, i. e. the system is powered having been off.

HINT: If diagnostic trouble code (DTC) ICM-DC01 is intermittent, read off the status of the ring break diagnostic from the frozen values in Vehicle communication. 

Check the communication on the MOST network by bypassing the control modules one by one on the MOST network as follows:

• Ignition off
• Disconnect the MOST connector from the relevant control module
• Connect the MOST cable to special tool see 9512867
• Ignition on
• Activate the infotainment system
• Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible. Click the VCT2000 symbol to read off the status of the MOST network.

If the communication on the MOST network is stable when a control module is disconnected, check the power supply and the ground terminal on the relevant control module. Check for intermittent faults. Try replacing the component if no fault is found.

• Continue 

  Refer to VERIFICATION 

Select the control module to be checked from the list.

1. Remote Digital Audio Receiver (RDAR). Refer to CHECKING CABLE AND COMPONENT 
2. Audio Control Module (AUD). Refer to CHECKING CABLE AND COMPONENT 
3. Integrated audio module (IAM). Refer to CHECKING CABLE AND COMPONENT 
4. Subwoofer Module (SUB). Refer to CHECKING THE CABLE AND COMPONENT 
5. Accessory USB unit (AUU). Refer to CHECKING THE CABLE AND COMPONENT 

Select the control module to be checked from the list.

1. Phone module (PHM). Refer to CHECKING CABLE AND COMPONENT 
2. Global positioning system module (GPS). Refer to CHECKING CABLE AND COMPONENT 
3. Multimedia module (MMM). Refer to CHECKING CABLE AND COMPONENT 
4. Infotainment Control Module (ICM). Refer to CHECKING CABLE AND COMPONENT 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Disconnect the MOST connector from Remote Digital Audio Receiver (RDAR).
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. The cause of the fault is then in the Remote Digital Audio Receiver (RDAR). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the power supply and ground connection for the Remote Digital Audio Receiver (RDAR).
• Check the MOST connection. Check for dirt, loose connections and damage
• If no fault is found, replace the Remote Digital Audio Receiver (RDAR).

Remedy as necessary.

Other information: 

• Remote Digital Audio Receiver (RDAR). See SIGNAL SPECIFICATION
• see OPTICAL WIRING HARNESS CHECK
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see LOCATION OF COMPONENTS
• see SATELLITE RADIO CONTROL MODULE

• Continue 

  Refer to VERIFICATION 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Disconnect the MOST connector from the audio module (AUD)
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. If this is the case, the fault cause is in the audio module (AUD). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the power supply and the ground terminal for the audio module (AUD)
• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the audio module (AUD) if no fault is found.

Remedy as necessary.

Other information: 

• To access or replace the audio module (AUD), see AUDIO MODULE (AUD), REPLACING
• see CHECKING THE VOLTAGE / GROUND TERMINAL
• see SIGNAL SPECIFICATION
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see OPTICAL WIRING HARNESS CHECK
• see LOCATION OF COMPONENTS

• Continue 

  Refer to VERIFICATION 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Unplug the MOST connector from the integrated audio module (IAM).
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. If this is the case, the fault cause is in the integrated audio module (IAM). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the integrated audio module (IAM) power supply and ground connection.
• Check the MOST connection. Check for dirt, loose connections and damage
• If no fault can be found, change the integrated audio module (IAM).

Remedy as necessary.

Other information: 

• see CONTROL MODULE GENERAL SOUND PLAYER
• see CHECKING THE SUPPLY VOLTAGE/GROUND TERMINAL
• see SIGNAL SPECIFICATION
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see OPTICAL WIRING HARNESS CHECK
• see LOCATION OF COMPONENTS

• Continue 

  Refer to VERIFICATION 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Disconnect the MOST connector from the phone module (PHM)
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. If this is the case, the fault cause is in the phone module (PHM). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the power supply and the ground terminal for the phone module (PHM)
• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the phone module (PHM) if no fault is found.

Remedy as necessary.

Other information: 

• see PHONE MODULE (PHM), REPLACING (2006-2010)
• see CHECKING VOLTAGE / GROUND CONNECTION
• see SIGNAL SPECIFICATION 
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see OPTICAL WIRING HARNESS CHECK
• see LOCATION OF COMPONENTS

• Continue 

  Refer to VERIFICATION 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Unplug the MOST connector from the global positioning system module (GPS).
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. If this is the case, the fault cause is in the global positioning system module (GPS). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the global positioning system module (GPS) power supply and ground connection.
• Check the MOST connection. Check for dirt, loose connections and damage
• If no fault can be found, change the global positioning system module (GPS).

Remedy as necessary.

Other information: 

• see GLOBAL POSITIONING SYSTEM MODULE (GPS)
• see CHECKING THE SUPPLY VOLTAGE/GROUND TERMINAL
• see SIGNAL SPECIFICATION
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see OPTICAL WIRING HARNESS CHECK
• see LOCATION OF COMPONENTS

• Continue 

  Refer to VERIFICATION 

Checking the fault cause 

Check the fault cause as follows:

1. Ignition off
2. Disconnect the MOST connector from the multimedia module (MMM)
3. Connect the MOST cable to special tool see 9512867
4. Ignition on
5. Activate the infotainment system
6. Check that the communication on the MOST network is functioning by reading off the status of the MOST locked parameter for at least 30 seconds. The parameter indicates whether the MOST network is closed and communication possible Click the VCT2000 symbol to read off the status of the MOST network.
7. If the parameter displays that the MOST network is not correctly connected, check the receiving control module in the same way as above.

The communication on the MOST network is working if the menu text is displayed. If this is the case, the fault cause is in the multimedia module (MMM). Continue the fault-tracing by checking the component.

The communication on the MOST network is not working if the menu text is not displayed. The fault cause is then in the MOST cable for the next control module. Continue the fault-tracing by checking the fiber optic cable.

Checking cable 

• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the MOST cable if no fault is found in the MOST terminal.

Checking the component 

• Check the power supply and the ground terminal for the multimedia module (MMM)
• Check the MOST connection. Check for dirt, loose connections and damage
• Replace the multimedia module (MMM) if no fault is found.

Remedy as necessary.

Other information: 

• To access / replace the multimedia module (MMM), see MULTIMEDIA MODULE (MMM), REPLACING
• For information about checking the power supply and ground terminal, see CHECKING THE VOLTAGE / GROUND TERMINAL (2007-2012)
• see SIGNAL SPECIFICATION
• For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
• see OPTICAL WIRING HARNESS CHECK
• see LOCATION OF COMPONENTS

• Continue 

  Refer to VERIFICATION 

• Ignition off
• Disconnect the MOST cable connector from the infotainment control module (ICM)
• Ignition on
• Activate the infotainment system.

  Check visually whether the infotainment control module (ICM) is emitting light from the MOST connector.

  The control module is defective if the infotainment control module (ICM) is not emitting light.

  If the infotainment control module (ICM) is transmitting light, the fault is in the MOST cable for the next control module.

  Check the MOST connection. Check for dirt, loose connections and damage.

  Replace the MOST cable if no fault is found in the MOST terminal.

  Remedy as necessary.

  Other information: 

  • To access / replace the infotainment control module (ICM), see INFOTAINMENT CONTROL MODULE (ICM), REPLACING
  • For information about checking and replacing the MOST cable, see FIBER OPTIC CABLE HARNESS, REPAIRING
  • see LOCATION OF COMPONENTS
  Fig 2: Infotainment Control Module

  Courtesy of VOLVO CARS CORPORATION

• Continue 

  Refer to VERIFICATION