Toyota Yaris: Smart Key System (for Entry Function) / Back Door Entry Unlock Function does not Operate

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System (for Entry Function) / Back Door Entry Unlock Function does not Operate

DESCRIPTION

If the entry unlock function does not operate for the back door only, but the entry lock function operates, the request code is being transmitted properly from the back door. In this case, there may be a problem related to the open switch (connection between the back door opener switch assembly and certification ECU (smart key ECU assembly)).

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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 Entry Function) uses the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Entry Function) after confirming that the communication systems are functioning properly.
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Before replacing the certification ECU (smart key ECU assembly), refer to Precaution.
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After repair, confirm that no DTCs are output.
Check that there are no electrical key transmitter sub-assemblies in the vehicle.

PROCEDURE

1.	CHECK POWER DOOR LOCK CONTROL SYSTEM

(a) When the door control switch on the multiplex network master switch assembly is operated, check that the back door lock and unlock according to the switch operation.

Click here

OK:

Back door lock/unlock operate normally.

GO TO POWER DOOR LOCK CONTROL SYSTEM

2.	READ VALUE USING GTS (TRUNK LID/BACK DOOR UNLOCK SWITCH)

(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
Trunk Lid/Back Door Unlock Switch	Back door opener switch assembly (open switch)	OFF or ON	OFF: Back door opener switch assembly (open switch) not pressed ON: Back door opener switch assembly (open switch) pressed	Displays whether the back door opener switch assembly is on or off. Use this Data List item to help determine if there is a switch malfunction when the entry back door open function does not operate.

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Trunk Lid/Back Door Unlock Switch

Back door opener switch assembly (open switch)

OFF or ON

OFF: Back door opener switch assembly (open switch) not pressed

ON: Back door opener switch assembly (open switch) pressed

Displays whether the back door opener switch assembly is on or off.
Use this Data List item to help determine if there is a switch malfunction when the entry back door open function does not operate.

Body Electrical > Smart Key > Data List

Tester Display
Trunk Lid/Back Door Unlock Switch

OK:

The GTS display changes correctly in response to the operation of the back door opener switch assembly.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

3.	CHECK HARNESS AND CONNECTOR (BACK DOOR OPENER SWITCH ASSEMBLY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

(a) Disconnect the O47 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the Y8 back door opener switch assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
O47-16 (TSW5) - Y8-3 (UL)	Always	Below 1 Ω
O47-16 (TSW5) or Y8-3 (UL) - Other terminals and body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT BACK DOOR OPENER SWITCH ASSEMBLY (OPEN SWITCH)

Click here

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPLACE BACK DOOR OPENER SWITCH ASSEMBLY

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DESCRIPTION If the entry lock and unlock functions do not operate for the back door only, the request code may not be being transmitted from the back door...

Other information:

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