Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001ARF5
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B2271; Ignition Hold Monitor Malfunction; 2019 - 2022 MY Avalon [04/2018 -        ]

DTC

B2271

Ignition Hold Monitor Malfunction

DESCRIPTION

This DTC is stored when a malfunction in the IG drive circuit or IG hold circuit of the certification ECU (smart key ECU assembly) or a malfunction in the IG output circuit between the output terminal of the certification ECU (smart key ECU assembly) and IG relay is detected.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B2271

Ignition Hold Monitor Malfunction

When either of the following conditions is met (1-trip detection logic*1):

  • The IG circuit of the certification ECU (smart key ECU assembly) is malfunctioning.*2
  • The IG hold circuit of the certification ECU (smart key ECU assembly) is malfunctioning.*3
  • There is a malfunction in a circuit outside of the certification ECU (smart key ECU assembly) circuit.
  • Certification ECU (smart key ECU assembly)
  • Instrument panel junction block assembly
  • Wire harness or connector

DTC Output Confirmation Operation:

  • Turn the engine switch on (IG).
  • *1: Only detected while a malfunction is present and the engine switch is on (IG).
  • *2: The IG circuit and IG hold circuit activate the IG relay.
  • *3: After the IG circuit turns on, even if the certification ECU (smart key ECU assembly) malfunctions, the IG hold circuit will maintain the power source mode in on (IG).

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Function when Malfunction Detected

The engine switch cannot be turned on (IG) (the engine cannot be started).

The power source mode cannot be changed to on (IG).

Related Data List and Active Test Items

DTC No.

Data List and Active Test

B2271

Power Source Control

  • IG Relay Monitor (Inside)
  • Latch Circuit

Starting Control

  • Ignition

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 2019 - 2022 MY Avalon [04/2018 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING

  • Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

    Click here 2019 - 2020 MY Avalon [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2021 - 2022 MY Avalon [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

  • 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))
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 4A instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G40-17 (IG1D) - 4A-17

Always

Below 1 Ω

G40-17 (IG1D) or 4A-17 - Other terminals and body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 4F instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4A-17 - 4F-13

Always

Below 1 Ω

4A-17 or 4F-13 - Other terminals

Always

10 kΩ or higher
NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

OK

5.

CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - IG2 NO. 1 RELAY)

(a) Remove the IG2 NO. 1 relay from the No.1 engine room relay block and No.1 junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4F-13 - No.1 engine room relay block and No.1 junction block assembly IG2 NO. 1 relay terminal 1

Always

Below 1 Ω

4F-13 or No.1 engine room relay block and No.1 junction block assembly IG2 NO. 1 terminal 1 - Other terminals and body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

INSPECT IG2 NO. 1 RELAY

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

Battery voltage not applied between terminals 1 and 2

10 kΩ or higher

3 - 5

Battery voltage applied between terminals 1 and 2

Below 1 Ω

*1

IG2 NO. 1 Relay
NG

REPLACE IG2 NO. 1 RELAY
OK

7.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 4D instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4A-17 - 4D-3

Always

20 Ω or higher

4A-17 or 4D-3 - Other terminals

Always

10 kΩ or higher
OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL