Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001ARF8
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): Power Source Mode does not Change to ON (IG); 2019 - 2022 MY Avalon [04/2018 -        ]

Power Source Mode does not Change to ON (IG)

DESCRIPTION

If the engine switch is pressed with the electrical key transmitter sub-assembly in the cabin, the certification ECU (smart key ECU assembly) receives a signal and changes the power source mode.

Related Data List and Active Test Items

Problem Symptom

Data List and Active Test

Power source mode does not change to on (IG) but does change to on (ACC)

Power Source Control

  • Power Supply Condition
  • IG Relay Monitor (Inside)
  • IG Relay Monitor (Outside)
  • IG 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

  • Make sure that no DTCs are output. If any DTCs are output, proceed to Diagnostic Trouble Code Chart.
  • If the smart key system (for Start Function, Gasoline Model) has been disabled, enable the system before performing troubleshooting.

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

  • Inspect the fuses of circuits related to this system before performing the following procedure.
  • 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 completing repairs, confirm that the problem does not recur.
  • After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."

PROCEDURE

1.

CHECK FOR DTC

(a) Using the Techstream, check for certification ECU (smart key ECU assembly) DTCs.

Body Electrical > Power Source Control > Trouble Codes

Body Electrical > Smart Key > Trouble Codes

Body Electrical > Starting Control > Trouble Codes

Result

Proceed to

DTCs are not output

A

Smart key system (for Start Function, Gasoline Model) DTCs are output

B
B

GO TO DIAGNOSTIC TROUBLE CODE CHART 2019 - 2020 MY Avalon [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): DIAGNOSTIC TROUBLE CODE CHART 2021 MY Avalon [08/2020 - 08/2021]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): DIAGNOSTIC TROUBLE CODE CHART 2022 MY Avalon [08/2021 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): DIAGNOSTIC TROUBLE CODE CHART

A

2.

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

G40-17 (IG1D) - Body ground

Engine switch off → Engine switch on (ACC)

1 V or less → 9 V or higher

*a

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))
NG

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

OK

3.

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

(a) Disconnect the 4A, 4D, 4L and 4K instrument panel junction block assembly connectors.

(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

4D-3 - Body ground

Always

Below 1 Ω

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

Always

10 kΩ or higher

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

4K-1 - Body ground

Always

11 to 14 V

4L-1 - Body ground

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1-NO. 1, IG1-NO. 2, IG2-NO. 2 RELAY)

(a) Remove the instrument panel junction block assembly.

Click here 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

(b) Connect all of the instrument panel junction block assembly connectors.

(c) Connect the G40 certification ECU (smart key ECU assembly) connector.

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

*a

Component with harness connected

(Instrument Panel Junction Block Assembly)

-

-

Standard Voltage:

Tester Connection

Condition

Specified Condition

4H-35 - Body ground

Engine switch on (IG)

11 to 14 V

4F-2 - Body ground

Engine switch on (IG)

11 to 14 V

4F-15 - Body ground

Engine switch on (IG)

11 to 14 V
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) Disconnect the 4F instrument panel junction block assembly connector.

(c) 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

No. 1 engine room relay block and No. 1 junction block assembly IG2 NO. 1 relay terminal 2 - Body ground

Always

Below 1 Ω

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

USE SIMULATION METHOD TO CHECK

NG

REPLACE IG2 NO. 1 RELAY