Diagnosis Procedure
1.CHECK CONNECTOR
Turn the ignition switch OFF.
Disconnect the battery cable from the negative terminal.
Check the following terminals and connectors for damage, bend and loose connection (connector side and harness side).
Harness connector M1
Harness connector E30
2.CHECK HARNESS CONTINUITY (OPEN CIRCUIT)
Disconnect the following harness connectors.
A/C auto amp.
Harness connectors M1 and E30
Check the continuity between the A/C auto amp. harness connector and the harness connector.

3.CHECK HARNESS CONTINUITY (OPEN CIRCUIT)
Disconnect the connector of ABS actuator and electric unit (control unit).
Check the continuity between the harness connector and the ABS actuator and electric unit (control unit) harness connector.

Main line between HVAC and A-bag circuit
ECM branch line circuitU1300 AV comm circuit
Description
U1300 is indicated when a communication signal malfunction occurs. U1300 is
indicated along with DTCs that identify components connected to the AV
control unit through communication lines. Determine the possible malfunction
cause from the table below.
SELF-DIAGNOSIS RESULTS DISPL ...
Inside mirror
Wiring Diagram - Without Homelink Universal Transceiver
Wiring Diagram - With Homelink Universal Transceiver
...
Bluetooth control unit
Removal and Installation
REMOVAL
Disconnect the battery negative terminal.
Remove the trunk upper finisher. Refer to INT-36, "Exploded View".
Remove the parcel shelf finisher. Refer to INT-28, "Removal and
Installation".
From inside the passenger compartment, remove the bracket screw ...