Faulty Communication

Diagnostic trouble code (DTC) ICM-DC00 is stored in the event of an internal fault in the infotainment control module (ICM) preventing the transmitting and receiving diodes from sending sound pulses on the MOST network.

For faults when messages cannot be sent on the MOST network, diagnostic trouble code (DTC) ICM-DC02 is stored.

Causes of this fault may be that:

• a control module, except the infotainment control module (ICM), has a defective optical connector
• a control module has an internal fault which means that the optical connection stops working
• a control module on the MOST network is not powered. If there is no power supply, the optical connecter stops transmitting light
• the optical cable is damaged or there is an open-circuit. This fault can occur if the bend radius of the cable is too small or if the cable is kinked or trapped
• there is dirt or oil on the optical connectors which impedes the light
• the connection to a control module has come loose
• the fiber optic terminals in the connector are cross-connected
• there is a loose connection because the fiber optical wiring is incorrectly installed or the fiber optic terminal pin has been pressed back in the connector
• a bridging connector has come loose or is damaged.

Ring break diagnostics are used to remedy diagnostic trouble code (DTC) ICM-DC02. If a break is discovered in the MOST network after running a ring break diagnostic, diagnostic trouble code (DTC) ICM-DC01 will be stored in the infotainment control module (ICM). If this is the case, the position of the open-circuit and control module location, can be read off from the infotainment control module (ICM).