THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B228B; System Voltage or GND Energization Malfunction; 2019 - 2022 MY Avalon [04/2018 - ]

Last Modified: 08-21-2023	6.11:8.1.0	Doc ID: RM100000001ARFD
Model Year Start: 2019	Model: Avalon	Prod Date Range: [04/2018 - ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B228B; System Voltage or GND Energization Malfunction; 2019 - 2022 MY Avalon [04/2018 - ]

DTC

B228B

System Voltage or GND Energization Malfunction

SYSTEM DESCRIPTION

This DTC is stored when there is a malfunction in the certification ECU (smart key ECU assembly) battery power supply circuit or ground circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B228B	System Voltage or GND Energization Malfunction	A malfunction is detected in the certification ECU (smart key ECU assembly) battery power supply circuit or ground circuit. (1-trip detection logic*)	AM2 fuse Wire harness or connector	DTC Output Confirmation Operation: Drive the vehicle.

*: Only detected while a malfunction is present.

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Function when Malfunction Detected
The engine stopped while driving.	-

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B228B	-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the engine switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function, Gasoline Model) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function, Gasoline Model) after confirming that the communication systems are functioning properly.
Click here
Inspect the fuses of circuits related to this system before performing the following procedure.
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (POWER SOURCE)

(a) Disconnect the G40 certification ECU (smart key ECU assembly) connector.

*a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
G40-4 (+B) - Body ground	Always	11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE

OK

2.	CHECK HARNESS AND CONNECTOR (GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G40-18 (E) - Body ground	Always	Below 1 Ω

*a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

OK

END (TEMPORARY CONNECTION FAILURE IS SUSPECTED)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE