Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001BTB7
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM (for HV Model): B1556; Extension Module Malfunction 2; 2019 - 2022 MY Avalon HV [04/2018 -        ]

DTC

B1556

Extension Module Malfunction 2

DESCRIPTION

These DTCs are stored when a malfunction occurs in the Navigation ECU.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1556

Extension Module Malfunction 2

When any of the following conditions is met:

  • Internal power supply malfunction
  • Internal hard drive malfunction
  • EEPROM error
  • Storage malfunction

Navigation ECU

CAUTION / NOTICE / HINT

NOTICE:

When replacing the navigation ECU, always replace it with a new one. If a navigation ECU which was installed to another vehicle is used, the following may occur:

  • A communication malfunction DTC may be stored.
  • The navigation ECU may not operate normally.

PROCEDURE

1.

CHECK DTC

(a) Clear the DTCs.

Body Electrical > Navigation System > Clear DTCs

(b) Recheck for DTCs and check that no DTCs are output.

Body Electrical > Navigation System > Trouble Codes

OK:

No DTCs are output.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE NAVIGATION ECU 2019 - 2020 MY Avalon Avalon HV [04/2018 - 08/2020]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION ECU: REMOVAL 2021 - 2022 MY Avalon Avalon HV [08/2020 -        ]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION ECU: REMOVAL