DTC 01-D6 No Master; DTC 01-D7 Connection Check Error: Description

WARNING: This page is about a different car, the 2009 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

DTC DETECTION CONDITION CHART

DTC No.	DTC Detection Condition	Trouble Area
01-D6 *1	When either of the following conditions is met: The device that stores (stored) the code has (had) been disconnected while the ignition switch is ON or ACC. The master device has (had) been disconnected when this code is stored.	Radio receiver power source circuit Power source circuit of the component which has stored this code AVC-LAN circuit between the radio receiver and the component which has stored this code Component which has stored this code Radio receiver
01-D7 *2	When either of the following conditions is met: The device that stored the code has (had) been disconnected after the engine starts (started). The master device has (had) been disconnected when this code is (was) stored.
HINT: 1: Even if no fault is present, this trouble code may be stored depending on the battery condition or engine start voltage. 2: When 210 seconds have elapsed after disconnecting the power supply connector of the master component with the ignition switch ON or ACC, this code is stored.

NOTE:

Before starting troubleshooting, be sure to clear the DTCs stored due to the reasons described in the HINT above. Then, check for DTCs and troubleshoot according to the output DTCs.
The radio receiver is the master unit.
Be sure to clear and recheck for the DTCs after the inspection is completed to confirm that no DTCs are output.