U1300 is indicated when malfunction occurs in communication signal of multi AV system. Indicated simultaneously, without fail, with the malfunction of control units connected to AV control unit with communication line. Determine the possible malfunction cause from the table below.
SELF-DIAGNOSIS RESULTS DISPLAY ITEM

DTC | Display contents of CONSULT‐III | DTC detection condition | Possible malfunction factor
U1300 U1240 |

- AV COMM CIRCUIT [U1300]
- SWITCH CONN [U1240]

When either one of the following items are detected:

- multifunction switch power supply and ground circuits are malfunctioning.
- AV communication circuits between AV control unit and multifunction switch are malfunctioning.

- Multifunction switch power supply and ground circuits.
- AV communication circuits between AV control unit and multifunction switch.