DTC B1591: No Response from Audio HU; DTC B15D1: Audio HU Disconnected: Description

The display and navigation module display and radio receiver assembly are connected by the MOST communication line.

When a MOST communication error occurs between the display and navigation module display and radio receiver assembly, this DTC will be stored.

DTC Code	DTC Detection Condition	Trouble Area
B1591	Within the time-out period, there was no response from the radio receiver assembly to the following requests from the master unit: System inspection request System inspection result request Diagnostic memory request	Radio receiver assembly Display and navigation module display Harness or connector
B15D1*	When either of the conditions below is met: Radio receiver assembly is/was not connected while the engine switch is on (IG or ACC). Communication between the master unit and the radio receiver assembly is not possible when the engine is started.

HINT:

*: Even if no fault is present, this DTC may be stored depending on the battery condition or engine start voltage.
The display and navigation module display is the master unit.