Toyota Yaris: Smart Key System (for Start Function) / New Key cannot be Registered

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System (for Start Function) / 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), ID code box (immobiliser code ECU), electrical key transmitter sub-assembly, steering lock ECU (steering lock actuator or upper bracket assembly), smart 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 ID code box (immobiliser code ECU) have been replaced.
The certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) 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).
When using the GTS with the ignition switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Key. While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS 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
Before replacing the electrical key transmitter sub-assembly, certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) 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.
If registration of an electrical key transmitter sub-assembly cannot be performed, refer to the Registration.

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 auxiliary battery before checking for DTCs.

OK:

DTCs are not output.

GO TO DIAGNOSTIC TROUBLE CODE CHART

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

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

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 4	Number of registered electrical key transmitter sub-assemblies	Up to 4 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 GTS display.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

3.	READ VALUE USING GTS (VEHICLE CONTROL HISTORY (ROB))

(a) Read the Vehicle Control History (RoB) according to the display on the GTS.

Body Electrical > Smart Key > Utility

Tester Display
Vehicle Control History (RoB)

Registration Function (Reason for Non-operation):

Parameter Name	Detection Condition	Trouble Area	Proceed to
Cannot Enter 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
Cannot Enter Registration Mode (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
Registration Limit	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) ID code box (immobiliser code ECU)	L
Cannot Enter Registration Mode (ID Code Box Availability Not Confirmed)	A registration request was sent even though the existence of an ID code box is unknown.	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU)	M
Cannot Enter Registration Mode (Vehicle Speed > 5 km/h) (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 (3 mph) or more.	Certification ECU (smart key ECU assembly)	C
ECU Code Confirmation Failed (No Response from Connected ECUs)	The steering lock ECU (steering lock actuator or upper bracket assembly) was not connected.	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU) Steering lock ECU (steering lock actuator or upper bracket assembly)	D
ECU Code Confirmation Failed (L Code Certification Failed)	The L codes registered in the ID code box (immobiliser code ECU) and steering lock ECU (steering lock actuator or upper bracket assembly) did not match.	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU) Steering lock ECU (steering lock actuator or upper bracket assembly)	N
ECU Code Confirmation Failed (L Code Succeeded, S Code Failed)	L code verification was successful but the S code stored in the ID code box (immobiliser code ECU) and certification ECU (smart key ECU assembly) did not match.	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU)	L
ECU Code Confirmation Failed (Too Many Keys Registered in ID Code Box)	The number of electrical key transmitter sub-assemblies registered in the ID code box (immobiliser code ECU) was more than 4.	ID code box (immobiliser code ECU)	O
Confirmation Failed for All Registered Keys (Immobilizer Certification Failed)	All of the registered electrical key transmitter sub-assemblies were incorrectly held near the engine switch and the certification ECU (smart key ECU assembly) could not complete verification.	Certification ECU (smart key ECU assembly) Engine switch	F
Confirmation Failed for All Registered Keys (Some Keys Unconfirmed)	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	G
Confirmation Failed for All Registered Keys (Key Information Malfunction)	All of the registered electrical key transmitter sub-assemblies were held near the engine switch, but key ID information was not stored by the certification ECU (smart key ECU assembly).	Key registration failure	E
New Key ID Registration Failed (Immobilizer Certification Failed)	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) Engine switch	E
New Key ID Registration Failed (Vehicle ID did not Match)	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	H
New Key ID Registration Failed (Conditions Other than Vehicle ID not Met)	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	H
New Key ID Registration Failed (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)	I
New Key ID Registration Failed (ID Code Writing Failed)	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
New Key ID Registration Failed (Key Information Malfunction)	An unregistered electrical key transmitter sub-assembly was held near the engine switch, but key ID information was not stored by the certification ECU (smart key ECU assembly).	Key registration failure	H
No Response from Connected ECUs when Registering L/S Codes	The certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly) was not connected.	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU) Steering lock ECU (steering lock actuator or upper bracket assembly)	D
S Code Registration Failed (Certification ECU, ID Code Box)	The S code could not be stored by the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU).	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU)	L
L Code Registration Failed (ID Code Box, Steering Lock ECU)	The L code could not be stored by the steering lock ECU (steering lock actuator or upper bracket assembly) or ID code box (immobiliser code ECU).	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU) Steering lock ECU (steering lock actuator or upper bracket assembly)	N
ECU ID Verification Error	The code received from the ID code box (immobiliser code ECU) when the S code is registered does not match the code of the certification ECU (smart key ECU assembly).	Certification ECU (smart key ECU assembly) ID code box (immobiliser code ECU)	L
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 (immobiliser code ECU) was provided in the vehicle to EEPROM.	Certification ECU (smart key ECU assembly)	B
New Key ID Registration Stopped (Security Access Malfunction)	Communication error	Communication error between the GTS and key registration server	J
New Key ID Registration Stopped (Certification ECU Type Malfunction)	The electrical key transmitter sub-assembly is not compatible with the certification ECU (smart key ECU assembly).	Certification ECU (smart key ECU assembly)	B
New Key ID Registration Stopped (Key Type Malfunction 1)	The electrical key transmitter sub-assembly is not compatible with the registration mode.	Electrical key transmitter sub-assembly	K
New Key ID Registration Stopped (Key Type Malfunction 2)	The electrical key transmitter sub-assembly is not compatible with the certification ECU (smart key ECU assembly).	Electrical key transmitter sub-assembly	K

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

GO TO STEP 5

CHECK FOR DTC B278588

CHECK FOR DTC B27841C, B278E87

GO TO STEP 6

GO TO STEP 10

GO TO STEP 12

NEW KEY REGISTRATION FAILED, CHECK THE KEY

PERFORM REREGISTRATION

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

GO TO STEP 13

CHECK FOR DTC B278987

GO TO STEP 14

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

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 GTS (VEHICLE SPEED METER)

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

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.	CHECK FOR REGISTERD 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

7.	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 9

8.	REREGISTRATION

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

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.
Refer to Registration.
Click here

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 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)

9.	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

10.	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

11.	REREGISTRATION

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

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.
Refer to Registration.
Click here

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 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)

12.	PERFORM 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)

13.	CHECK 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 ID CODE BOX (IMMOBILISER CODE ECU)

14.	CHECK 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)

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

(a) Temporarily replace the steering lock ECU (steering lock actuator or upper bracket assembly) with a new one and register the electrical key transmitter sub-assemblies.

Click here

OK:

All of the electrical key transmitter sub-assemblies could be registered to the new steering lock ECU (steering lock actuator or upper bracket assembly) successfully.

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

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

Power Source Mode does not Change to ON (ACC)

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...

Additional Key cannot be Registered

DESCRIPTION If additional registration is not possible, a malfunction of the electrical key transmitter sub-assembly, certification ECU (smart key ECU assembly), engine switch, No...

Other information:

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual: Operation not Accepted Even If Air Conditioning Switch is Operated

DESCRIPTION If the air conditioning system cannot be operated using the air conditioning control assembly, the following factors may be the cause. Symptom Factor Air conditioning system cannot be operated using air conditioning control assembly (With the exception of the switch indicators, no inputs are reflected when other switches operated) LIN communication malfunction between air conditioning amplifier assembly and air conditioning control assembly Short to +B or ground in air conditioning amplifier assembly circuit Air conditioning amplifier assembly malfunction Air conditioning control assembly malfunction Harness or connector WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to this system before performing the following procedure...

Toyota Yaris XP210 (2020-2025) Owner's Manual: Front Passenger’s Seat Child-Restraint System Installation

Make sure the ignition is switched off. Slide the seat as far back as possible. Remove the head restraint. Place the child-restraint system on the seat without putting your weight on the seat and fasten the seat belt. See the manufacturer’s instructions on the child-restraint system for belt routing instructions...

Toyota Yaris: Smart Key System (for Start Function) / New Key cannot be Registered

Power Source Mode does not Change to ON (ACC)

Additional Key cannot be Registered

Other information:

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual: Operation not Accepted Even If Air Conditioning Switch is Operated

Toyota Yaris XP210 (2020-2025) Owner's Manual: Front Passenger’s Seat Child-Restraint System Installation

Categories

Turning the Engine Off