Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001B2NS
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): Unable to Unlock Steering Wheel (Hybrid Control System cannot Start); 2019 - 2022 MY Avalon HV [04/2018 -        ]

Unable to Unlock Steering Wheel (Hybrid Control System cannot Start)

DESCRIPTION

The steering lock actuator or upper bracket assembly activates the steering lock motor and moves the lock bar into the steering column to lock the steering.

The steering may not unlock when the lock bar gets stuck in the lock hole of the steering column. In this case, if the power switch is turned on (IG) while shaking the steering wheel, as is done for a vehicle with a mechanical key, the lock bar will be unlocked. If the certification ECU (smart key ECU assembly) or hybrid vehicle control ECU is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the hybrid control system cannot be started.

Related Data List and Active Test Items

Problem Symptom

Data List Item

Active Test Item

Unable to unlock steering wheel (Hybrid control system cannot start)

Smart Key

  • Unlock Request Receive
  • L Code Check
  • Steering Unlock

-

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.
  • Perform either of the following operations to lock/unlock the steering:
    • To unlock the steering, carry the electrical key transmitter sub-assembly and turn the power switch on (ACC) or on (IG).
    • To lock the steering, turn the power switch off with the shift lever in P, and then open a door.
  • The smart key system (for Start Function, HV 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, HV Model) after confirming that the communication systems are functioning properly.

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

  • After performing repairs, confirm that the problem does not recur.
  • Make sure that no DTCs are output. If any DTCs are output, proceed to the Diagnostic Trouble Code Chart.

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

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

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

  • When disconnecting the cable from the negative (-) auxiliary battery terminal, some systems need to be initialized after the cable is reconnected.

    Click here 2019 - 2020 MY Avalon Avalon HV [04/2018 - 08/2020]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION 2021 MY Avalon Avalon HV [08/2020 - 08/2021]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION 2022 MY Avalon Avalon HV [08/2021 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

  • If the steering lock ECU (steering lock actuator or upper bracket assembly) is replaced, be sure to confirm that the steering is unlocked by turning the steering wheel to the left and right before starting the hybrid control system. This function prevents the hybrid control system from starting while the steering is locked. If the steering is locked for any reason, open and close a door with the power switch off, and then unlock the steering by pressing the power switch.

PROCEDURE

1.

CHECK POWER SWITCH (SWITCH CONDITION)

(a) Check the power source mode change.

(1) When the electrical key transmitter sub-assembly is inside the vehicle and the shift lever is in P, check that pressing the power switch with the brake pedal released causes the power source mode to change as follows:

OK:

Off → On (ACC) → On (IG) → Off

NG

GO TO OTHER PROBLEM 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): PROBLEM SYMPTOMS TABLE 2021 - 2022 MY Avalon HV [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): PROBLEM SYMPTOMS TABLE

OK

2.

CHECK INDICATOR

(a) With the power switch on (IG), check that Steering Lock active is displayed on the multi-information display in the combination meter assembly.

Result

Proceed to

Steering Lock active is displayed.

A

Steering Lock active is not displayed.

B

B

GO TO STEP 4

A

3.

CHECK STEERING UNLOCK

(a) Turn the steering wheel left and right, and then press the power switch.

(b) Check that the steering is unlocked.

Result

Proceed to

The steering is unlocked.

A

The steering is not unlocked.

B

A

USE SIMULATION METHOD TO CHECK

B

4.

CHECK FOR DTC

(a) Using the Techstream, check if the certification ECU (smart key ECU assembly) DTC is output.

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTCs are not output.

A

DTCs are output.

B

B

GO TO DIAGNOSTIC PROCEDURE INDICATED BY OUTPUT DTC

A

5.

READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Smart Key / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Unlock Request Receive

Status of steering unlock command from certification ECU (smart key ECU assembly)

OK or NG

OK: Certification ECU (smart key ECU assembly) sends steering unlock command (within 10 seconds of power switch turned on (ACC) or on (IG), or of hybrid control system start operation performed)

NG: Certification ECU (smart key ECU assembly) does not send steering unlock command (power switch not turned on (ACC) or on (IG), and hybrid control system start operation not performed)

  • The hybrid control system cannot be started when an unlock request signal cannot be received.
  • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

Body Electrical > Smart Key > Data List

Tester Display

Unlock Request Receive

OK:

Within 10 seconds of turning the power switch on (ACC) or on (IG) or starting the hybrid control system, the Data List item changes to "OK".

NG

GO TO STEP 11

OK

6.

READ VALUE USING TECHSTREAM (L CODE CHECK)

(a) Read the Data List according to the display on the Techstream.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

L Code Check

Verification result between certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator or upper bracket assembly)

OK or NG

OK: Verification result normal

NG: Verification result abnormal

When NG is displayed:

  • The ID code for the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly) is not registered, or the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly) is malfunctioning.
  • The steering cannot be locked.
  • The steering cannot be unlocked (the hybrid control system cannot be started).

Body Electrical > Smart Key > Data List

Tester Display

L Code Check

OK:

OK is displayed on the Techstream.

HINT:

Reasons for verification failure:

  • The steering lock ECU (steering lock actuator or upper bracket assembly) or certification ECU (smart key ECU assembly) is malfunctioning.
  • There is a problem with the communication between ECUs.
  • An ECU is replaced, but is not registered.
  • An ECU is replaced with an ECU which has a code already stored in it.
NG

REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

for Manual Tilt and Manual Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Manual Tilt and Manual Telescopic Steering Column): DISASSEMBLY

for Power Tilt and Power Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Power Tilt and Power Telescopic Steering Column): DISASSEMBLY

OK

7.

CHECK HARNESS AND CONNECTOR (POWER SOURCE AND GROUND)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G43-1 (GND) - Body ground

Always

Below 1 Ω

NOTICE:

If the result is not as specified, check for looseness in the ground cable connection.

Standard Voltage:

Tester Connection

Condition

Specified Condition

G43-7 (B) - Body ground

Power switch off

11 to 14 V

*a

Component with harness connected

(Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.

CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

(a) Move the shift lever to P and turn the power switch off.

(b) Check the signal waveform according to the condition(s) in the table below.

*a

Component with harness connected

(Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

*b

Steering lock motor not operating

*c

Steering lock motor operating

*d

Waveform

OK:

Tester Connection

Condition

Tool Setting

Specified Condition

G43-3 (IGE) - G43-1 (GND)

2 V/DIV., 200 ms./DIV.

Steering lock motor not operating → Operating → Not operating

Pulse generation

(See waveform)

HINT:

  • When taking measurements when the lock motor is stopped, it is not necessary to perform any operations.
  • In order to take measurements when the lock motor is operating, perform either of the following operations:
    • To unlock the steering, carry the electrical key transmitter sub-assembly and turn the power switch on (ACC) or on (IG).
    • To lock the steering, turn the power switch off with the shift lever in P, and then open a door.
OK

REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

for Manual Tilt and Manual Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Manual Tilt and Manual Telescopic Steering Column): DISASSEMBLY

for Power Tilt and Power Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Power Tilt and Power Telescopic Steering Column): DISASSEMBLY

NG

9.

CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

(a) Disconnect the G43 steering lock ECU (steering lock actuator or upper bracket assembly) connector.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G43-3 (IGE) - G40-25 (SLR+)

Always

Below 1 Ω

G43-3 (IGE) or G40-25 (SLR+) - Other terminals and body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.

CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

(a) Connect the G43 steering lock ECU (steering lock actuator or upper bracket assembly) connector.

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

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

G43-3 (IGE) - Body ground

Power switch off

11 to 14 V

*a

Component with harness connected

(Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

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 STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

for Manual Tilt and Manual Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Manual Tilt and Manual Telescopic Steering Column): DISASSEMBLY

for Power Tilt and Power Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Power Tilt and Power Telescopic Steering Column): DISASSEMBLY

11.

CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

G43-4 (SLP1) - Body ground

Steering locked

11 to 14 V

*a

Component with harness connected

(Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

NG

GO TO STEP 13

OK

12.

READ VALUE USING TECHSTREAM (STEERING UNLOCK)

(a) Turn the power switch off.

(b) Check that the steering is locked.

(c) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

HINT:

When using the Techstream with the power switch off, connect the Techstream to the vehicle 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 Model Code "KEY REGIST" 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.

(e) Enter the following menus: Body Electrical / Smart Key / Data List.

(f) Read the Data List according to the display on the Techstream.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Steering Unlock

Steering lock ECU (steering lock actuator or upper bracket assembly) unlock confirmation status

Unset or Set

Unset: Unlock not confirmed

Set: Unlock confirmed

When Unset is displayed, the steering is not unlocked (the hybrid control system cannot be started).

Body Electrical > Smart Key > Data List

Tester Display

Steering Unlock

OK:

Set is displayed on the Techstream.

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 STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

for Manual Tilt and Manual Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Manual Tilt and Manual Telescopic Steering Column): DISASSEMBLY

for Power Tilt and Power Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Power Tilt and Power Telescopic Steering Column): DISASSEMBLY

13.

CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

(a) Disconnect the G43 steering lock ECU (steering lock actuator or upper bracket assembly) connector.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G43-4 (SLP1) - G40-14 (SLP)

Always

Below 1 Ω

G43-4 (SLP1) or G40-14 (SLP) - Other terminals and body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

14.

READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE)

(a) Replace the steering lock ECU (steering lock actuator or upper bracket assembly) with a new one.

for Manual Tilt and Manual Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Manual Tilt and Manual Telescopic Steering Column): DISASSEMBLY

for Power Tilt and Power Telescopic Steering Column: Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; STEERING COLUMN: STEERING COLUMN ASSEMBLY (for Power Tilt and Power Telescopic Steering Column): DISASSEMBLY

(b) Perform registration.

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

(c) Turn the power switch on (IG).

(d) Use the Data List to check if the steering lock request is functioning properly.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Unlock Request Receive

Status of steering unlock command from certification ECU (smart key ECU assembly)

OK or NG

OK: Certification ECU (smart key ECU assembly) sends steering unlock command (within 10 seconds of power switch turned on (ACC) or on (IG), or of hybrid control system start operation performed)

NG: Certification ECU (smart key ECU assembly) does not send steering unlock command (power switch not turned on (ACC) or on (IG), and hybrid control system start operation not performed)

  • The hybrid control system cannot be started when an unlock request signal cannot be received.
  • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

Body Electrical > Smart Key > Data List

Tester Display

Unlock Request Receive

OK:

Within 10 seconds of turning the power switch on (ACC) or on (IG) or starting the hybrid control system, the Data List item changes to "OK".

OK

END (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) WAS)

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