Toyota Avalon (XX50): Immobiliser System does not Operate Properly. New Key cannot be Registered. New Key Registration Warning Message is not Displayed

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System(for Start Function, Gasoline Model) / Immobiliser System does not Operate Properly. New Key cannot be Registered. New Key Registration Warning Message is not Displayed

Immobiliser System does not Operate Properly

DESCRIPTION

The immobiliser function compares the ID code that is registered in the certification ECU (smart key ECU assembly) with the ID code of the transponder chip that is embedded in the electrical key transmitter sub-assembly.

WIRING DIAGRAM

Click here

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
Before replacing the ECM or certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".
Make sure that no DTCs are output. If any DTCs are output, proceed to the Diagnostic Trouble Code Chart.

HINT:

If an immobiliser function or SFI system DTC is output, first perform troubleshooting for the immobiliser function or SFI system DTC.

PROCEDURE

1.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Smart Key > Trouble Codes Powertrain > Engine > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTCs are output	B

GO TO DIAGNOSTIC TROUBLE CODE CHART

2.	READ VALUE USING TECHSTREAM (IMMOBILISER FUEL CUT STATUS)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Powertrain / Engine / Data List.

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

Powertrain > Engine > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Immobiliser Fuel Cut Status	Status of immobiliser fuel cut	OFF or ON	-	-

Powertrain > Engine > Data List

Tester Display
Immobiliser Fuel Cut Status

OK:

OFF is displayed after the engine is started.

GO TO SFI SYSTEM

3.	CHECK WHETHER ENGINE STARTS

(a) Check that the engine starts 5 seconds after the engine switch turned on (IG).

OK:

Engine starts normally.

USE SIMULATION METHOD TO CHECK

4.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM)

(a) Disconnect the A10 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the A18 ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A10-3 (EFII) - A18-45 (IMO)	Always	Below 1 Ω
A10-4 (EFIO) - A18-59 (IMI)	Always	Below 1 Ω
A10-3 (EFII) or A18-45 (IMO) - Other terminals and body ground	Always	10 kΩ or higher
A10-4 (EFIO) or A18-59 (IMI) - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK ECM (TERMINAL EFIO AND EFII)

(a) Connect the A10 certification ECU (smart key ECU assembly) connector.

(b) Connect the A18 ECM connector.

*a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))	*b	Approximately 160 ms
*c	Approximately 270 ms	*d	Approximately 40 ms
*e	Approximately 60 ms	*f	Waveform (EFII)
*g	Waveform (EFIO)	*h	Waveform A
*i	Waveform B	*j	Waveform C
*k	Waveform A (detail)	-	-

NOTICE:

The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

OK:

Tester Connection	Condition	Tool Setting	Specified Condition
A10-3 (EFII) - Body ground	Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after battery cable disconnected and reconnected	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform (EFII))
A10-4 (EFIO) - Body ground	Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after battery cable disconnected and reconnected	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform (EFIO))

Tester Connection

Condition

Tool Setting

Specified Condition

A10-3 (EFII) - Body ground

Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after battery cable disconnected and reconnected

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform (EFII))

A10-4 (EFIO) - Body ground

Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after battery cable disconnected and reconnected

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform (EFIO))

Result	Proceed to
Normal waveform	A
Waveform A or C not output, or has abnormal wavelength or shape	B
Waveform B not output, or has abnormal wavelength or shape	C

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE ECM

6.	REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID.

HINT:

Refer to Registration.

Click here

7.	CHECK WHETHER ENGINE STARTS

(a) Check that the engine starts.

OK:

Engine starts normally.

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

New Key cannot be Registered

DESCRIPTION

If a new electrical key transmitter sub-assembly could not be registered, wave interference or a malfunction of the certification ECU (smart key ECU assembly), electrical key transmitter sub-assembly, steering lock ECU (steering lock actuator or upper bracket assembly) or door control receiver assembly is suspected.

The registration procedure to add another electrical key transmitter sub-assembly (without replacing any parts) is called "additional key ID registration".

If additional registration is not possible, refer to Additional Key cannot be Registered.

Click here

HINT:

If any of the following have been performed, registration of all electrical key transmitter sub-assemblies is necessary:

The certification ECU (smart key ECU assembly) has been replaced.
The certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator or upper bracket assembly) have been replaced.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

New registration mode can be entered only when no electrical key transmitter sub-assemblies are stored in the certification ECU (smart key ECU assembly).
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
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.
Before replacing the electrical key transmitter sub-assembly, certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly), refer to Registration.
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.
After repair, confirm that no DTCs are output.

PROCEDURE

1.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Smart Key > Trouble Codes

NOTICE:

If a malfunction occurs, do not remove/install the vehicle battery before checking for DTCs.

OK:

DTCs are not output.

GO TO DIAGNOSTIC TROUBLE CODE CHART

2.	READ VALUE USING TECHSTREAM (NUMBER OF REGISTERED KEY CODES)

(a) Connect the Techstream to the DLC3.

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

(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
Number of Registered Key Codes	Number of registered electrical key transmitter sub-assemblies	0 to 8	Number of registered electrical key transmitter sub-assemblies	Up to 7 electrical key transmitter sub-assemblies can be registered

Body Electrical > Smart Key > Data List

Tester Display
Number of Registered Key Codes

HINT:

A new certification ECU (smart key ECU assembly) will be have no electrical key transmitter sub-assemblies registered.

OK:

"0" is displayed on the Techstream display.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

3.	READ VALUE USING TECHSTREAM (OPERATION HISTORY LIST)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Smart Key / Utility / Operation History / Registration Function (Reason for Non-operation).

Body Electrical > Smart Key > Utility

Tester Display
Operation History

(e) Check the freeze frame data.

Registration Function (Reason for Non-operation):

Parameter Name	Detection Condition	Trouble Area	Proceed to
Failed Registration Mode	A registration request was sent while in another mode. During registration a different registration request was sent.	Certification ECU (smart key ECU assembly)	A
Vehicle ID not set	A vehicle ID has not been registered in the certification ECU (smart key ECU assembly).	Certification ECU (smart key ECU assembly)	B
Key Registration Max	A registration request is sent when the maximum number of electrical key transmitter sub-assemblies has already been registered.	Certification ECU (smart key ECU assembly)	C
Vehicle Speed Too High (This applies only when registration fails even though the vehicle is stationary. Make sure that the vehicle is stationary first.)	A registration request is sent with a vehicle speed of 5 km/h or more.	Certification ECU (smart key ECU assembly)	D
No ECU Response	The steering lock ECU (steering lock actuator or upper bracket assembly) was not connected.	Certification ECU (smart key ECU assembly) Steering lock ECU (steering lock actuator or upper bracket assembly)	E
L Code Verification Error	The L codes registered in the certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator or upper bracket assembly) did not match.	Certification ECU (smart key ECU assembly) Steering lock ECU (steering lock actuator or upper bracket assembly)	F
Key Verification: Max Number	The number of electrical key transmitter sub-assemblies registered in the certification ECU (smart key ECU assembly) was more than 7.	Certification ECU (smart key ECU assembly)	C
Key Verification: Amp Abnormal	Malfunction of the immobiliser amplifier, such as a short to ground.	Certification ECU (smart key ECU assembly) Engine switch	G
Key Verification: Read Error	Although a registered electrical key transmitter sub-assembly was held near the engine switch, immobiliser function certification was not successful.	Certification ECU (smart key ECU assembly) Electrical key transmitter sub-assembly	H
Unverified Key	Although all of the registered electrical key transmitter sub-assemblies had been held near the engine switch, electrical key transmitter sub-assembly registration was not possible due to immobiliser function certification not being successful.	Certification ECU (smart key ECU assembly) Electrical key transmitter sub-assembly	I
Transponder Key Amp Error	Malfunction of the immobiliser amplifier, such as a short to ground.	Certification ECU (smart key ECU assembly) Engine switch	G
New Key Registration Error	Although an unregistered electrical key transmitter sub-assembly was held near the engine switch, electrical key transmitter sub-assembly registration is not possible due to immobiliser function certification not being successful.	Certification ECU (smart key ECU assembly) Electrical key transmitter sub-assembly	J
New Key Vehicle ID Error	Although an unregistered electrical key transmitter sub-assembly was held near the engine switch, electrical key transmitter sub-assembly registration is not possible due to the vehicle ID not being stored successfully.	Certification ECU (smart key ECU assembly) Electrical key transmitter sub-assembly	J
New Key Registration Failed	After successful immobiliser function certification, time expired before smart recognition completion confirmation or a registration cancellation request was sent.	Certification ECU (smart key ECU assembly) Electrical key transmitter sub-assembly	J
New Key Already Registered	Although a registered electrical key transmitter sub-assembly was held near the engine switch, time expired or a registration cancellation request was sent.	Certification ECU (smart key ECU assembly)	K
New Key ID Code Error	Electrical key transmitter sub-assembly registration was not possible due to the certification ECU (smart key ECU assembly) not being able to store the information of the electrical key transmitter sub-assembly to EEPROM correctly.	Certification ECU (smart key ECU assembly)	B
No Response Registering L/S Code	The certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly) was not connected.	Certification ECU (smart key ECU assembly) Steering lock ECU (steering lock actuator or upper bracket assembly)	E
L Code Verification NG	The L code could not be stored by the steering lock ECU (steering lock actuator or upper bracket assembly).	Certification ECU (smart key ECU assembly) Steering lock ECU (steering lock actuator or upper bracket assembly)	F
Key Number Write Error	The certification ECU (smart key ECU assembly) could not store the number of electrical key transmitter sub-assemblies to EEPROM.	Certification ECU (smart key ECU assembly)	B
ID Code BOX Write Error	The certification ECU (smart key ECU assembly) could not store the information of whether the ID code box was provided in the vehicle to EEPROM.	Certification ECU (smart key ECU assembly)	B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

GO TO STEP 5

CHECK FOR DTC B2785

GO TO STEP 6

CHECK FOR DTC B278A or B2784

GO TO STEP 7

GO TO STEP 11

GO TO STEP 13

NEW KEY REGISTRATION FAILED, CHECK THE KEY

4.	CHECK REGISTRATION MODE

(a) Make sure that another mode or different registration mode is not selected.

OK:

Another mode or a different registration mode is not selected.

HINT:

If any mode has been selected, it is necessary to cancel the mode.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

PERFORM REREGISTRATION

5.	READ VALUE USING TECHSTREAM (VEHICLE SPEED METER)

(a) Connect the Techstream to the DLC3.

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

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

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

Body Electrical > Combination Meter > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Vehicle Speed Meter	Vehicle speed	Min.: 0, Max.: 255	Almost same as actual vehicle speed (Speedometer tester)	-

Body Electrical > Combination Meter > Data List

Tester Display
Vehicle Speed Meter

OK:

"0 km/h (0 mph)" is displayed when the vehicle is stationary.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

GO TO METER / GAUGE SYSTEM

6.	REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Temporarily replace the certification ECU (smart key ECU assembly) with a new one and register the electrical key transmitter sub-assemblies.

HINT:

For replacement.
Click here
For registration.
Click here

OK:

All of the electrical key transmitter sub-assemblies could be registered to the new certification ECU (smart key ECU assembly) successfully.

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

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

7.	CHECK ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

(a) Make sure that a registered electrical key transmitter sub-assembly is being used.

OK:

A registered electrical key transmitter sub-assembly is being used.

USE A REGISTERED ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY AND PERFORM REREGISTRATION

8.	CHECK NUMBER OF REGISTERED ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLIES

(a) Check the number of registered electrical key transmitter sub-assemblies.

Result	Proceed to
Only one electrical key transmitter sub-assembly is registered	A
2 or more electrical key transmitter sub-assemblies are registered	B

GO TO STEP 10

9.	REREGISTRATION

(a) Reregister the electrical key transmitter sub-assemblies using different order combinations.

Click here

HINT:

If there are 2 or more electrical key transmitter sub-assemblies, make sure that the number of order combinations is the same as the number of electrical key transmitter sub-assemblies so that each transmitter can be checked first.

Example: When there are 3 registered electrical key transmitter sub-assemblies (A, B and C).

Combination	Order*
1	A → B → C
2	B → C→ A
3	C → A → B

*: Except for the first electrical key transmitter sub-assembly, the remaining electrical key transmitter sub-assemblies can be checked in any order.

OK:

"Key Verification: Read Error" is not displayed.

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY (ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY HELD WHEN "Key Verification: Read Error" WAS DETECTED WAS DEFECTIVE)

10.	REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Temporarily replace the certification ECU (smart key ECU assembly) with a new one and register the electrical key transmitter sub-assemblies.

HINT:

For replacement.
Click here
For registration.
Click here

OK:

All of the electrical key transmitter sub-assemblies could be registered to the new certification ECU (smart key ECU assembly) successfully.

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

11.	CHECK FOR ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

(a) Check that all registered electrical key transmitter sub-assemblies are available.

OK:

No registered electrical key transmitter sub-assemblies are missing.

ERASE ALL REGISTERED ELECTRICAL KEY TRANSMITTERS EXCEPT ONE, THEN REGISTER THE REMAINING ELECTRICAL KEY TRANSMITTERS

12.	REREGISTRATION

(a) Register the electrical key transmitter sub-assemblies using different order combinations.

Click here

HINT:

Example: When there are 3 registered electrical key transmitter sub-assemblies (A, B and C).

Combination	Order*
1	A → B → C
2	B → C→ A
3	C → A → B

*: Except for the first electrical key transmitter sub-assembly, the remaining electrical key transmitter sub-assemblies can be checked in any order.

OK:

"Key Verification: Read Error" is not displayed.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY (ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY HELD WHEN "Key Verification: Read Error" WAS DETECTED WAS DEFECTIVE)

13.	REREGISTRATION

(a) Using an unregistered electrical key transmitter sub-assembly, register the ID.

Click here

OK:

The key ID can be registered.

END (ELECTRICAL KEY TRANSMITTER WAS DEFECTIVE)

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

New Key Registration Warning Message is not Displayed

DESCRIPTION

If the new key registration warning message is not displayed after an electrical key transmitter sub-assembly has been registered, there may be communication problem between the certification ECU (smart key ECU assembly) and combination meter assembly (meter ECU).

CAUTION / NOTICE / HINT

NOTICE:

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
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.
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output.
Check that there are no electrical key transmitter sub-assemblies in the vehicle.

PROCEDURE

1.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTCs are output	B

GO TO DIAGNOSTIC TROUBLE CODE CHART

2.	READ VALUE USING TECHSTREAM (FL DOOR COURTESY SW)

(a) Connect the Techstream to the DLC3.

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

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

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

Body Electrical > Main Body > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

FL Door Courtesy SW

Front door LH courtesy light switch signal

OFF or ON

OFF: Front door LH closed

ON: Front door LH open

Body Electrical > Main Body > Data List

Tester Display
FL Door Courtesy SW

Result	Proceed to
On the Techstream screen, ON or OFF is displayed accordingly.	A
On the Techstream screen, ON or OFF is not displayed accordingly.	B

GO TO LIGHTING SYSTEM

3.	CHECK METER / GAUGE SYSTEM

(a) With the electrical key transmitter sub-assembly in the vehicle and all of the doors closed, lock the doors using the entry lock function and check that the warning message is displayed on the multi-information display.

Result	Proceed to
The warning message is displayed on the multi-information display.	A
The warning message is not displayed on the multi-information display.	B

GO TO METER / GAUGE SYSTEM

4.	ADDITIONAL KEY REGISTRATION

(a) Clear all of the registered electrical key transmitter sub-assemblies except one and perform registration again.

Click here

5.	CHECK MULTI-INFORMATION DISPLAY

(a) With all of the doors closed, lock the doors using the entry lock function.

(b) Unlock the doors using the entry unlock function, open the driver door and check that the warning message is displayed on the multi-information display.

Result	Proceed to
The warning message is displayed on the multi-information display.	A
The warning message is not displayed on the multi-information display.	B

END (10 DAYS MAY HAVE ELAPSED SINCE AN ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY WAS REGISTERED)

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Dtc Check / Clear. Engine does not Start. How To Proceed With Troubleshooting

Operation Check. Parts Location. Power Source Mode does not Change to ON (ACC)

See More:

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