Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H8DX
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): Power Source Mode does not Change to ON (ACC); 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

Power Source Mode does not Change to ON (ACC)

DESCRIPTION

If the power 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 (ACC) but does change to on (IG)

Power Source Control

  • Power Supply Condition
  • ACC Relay Monitor

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the power 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) 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) after confirming that the communication systems are functioning properly.

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV 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) has been disabled, enable the system before performing troubleshooting.

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): CUSTOMIZE PARAMETERS

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

    Click here 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV 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."

HINT:

  • If interior verification is unsuccessful, Operation History may be stored.
  • If Operation History has been stored, refer to the Operation History List to determine the detection conditions and narrow down trouble areas.

Body Electrical > Smart Key > Utility

Tester Display

Operation History

PROCEDURE

1.

CHECK POWER SOURCE MODE

(a) Get into the vehicle while carrying the electrical key transmitter sub-assembly that has already been registered.

(b) Move the shift lever to P.

(c) Press the power switch with the brake pedal released and check that the power source mode changes.

Click here 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): OPERATION CHECK 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): OPERATION CHECK

Result

Proceed to

Power source mode cannot be changed

A

Power source mode can be changed

B
B

CHECK OPERATION HISTORY
A

2.

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

Result

Proceed to

DTCs are not output

A

Smart key system (for Start Function) DTCs are output

B
B

GO TO DIAGNOSTIC TROUBLE CODE CHART 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): DIAGNOSTIC TROUBLE CODE CHART 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): DIAGNOSTIC TROUBLE CODE CHART

A

3.

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

I1-16 (ACCD) - Body ground

Power switch off → Power 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) 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL

OK

4.

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

(a) Disconnect the I1 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the 4D, 4E and 4F instrument panel junction block assembly connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I1-16 (ACCD) - 4E-30

Always

Below 1 Ω

4F-3 - Body ground

Always

Below 1 Ω

I1-16 (ACCD) or 4E-30 - Other terminals and body ground

Always

10 kΩ or higher

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

4D-1 - Body ground

Power switch off

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (ACC RELAY)

(a) Remove the instrument panel junction block assembly.

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

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

(c) 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

4A-26 - Body ground

Power switch on (IG)

11 to 14 V
OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL