Toyota Yaris: Wireless Door Lock Control System / Wireless Door Lock Tuner Component Internal Failure (B124296)

Toyota Yaris XP210 (2020-2026) Reapir and Service Manual / Vehicle Interior / Door Lock / Wireless Door Lock Control System / Wireless Door Lock Tuner Component Internal Failure (B124296)

DESCRIPTION

The smart door control receiver assembly is used to receive radio waves related to the entry functions of the electrical key transmitter sub-assembly. The certification ECU (smart key ECU assembly) decodes the requested electrical key transmitter sub-assembly operation by identifying a key code based on the radio waves received via the smart door control receiver assembly. The smart door control receiver assembly receives a signal from the electrical key transmitter sub-assembly and sends signals to the main body ECU (multiplex network body ECU) through the certification ECU (smart key ECU assembly). (ex. If a door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU (multiplex network body ECU)).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B124296	Wireless Door Lock Tuner Component Internal Failure	Short to ground in RDAM terminal circuit between the certification ECU (smart key ECU assembly) and smart door control receiver assembly. Short to ground in RDAM terminal circuit when voltage (5 V) is not being output from terminal RCO	Wire harness or connector Smart door control receiver assembly 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.
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
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When replacing or inspecting the smart door control receiver assembly and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the smart door control receiver assembly, the performance of the entry function and wireless function may be affected.
This DTC is not stored within 10 seconds of the ignition switch being turned from on to off.
Make sure that there are no electrical key transmitter sub-assemblies in the vehicle.

PROCEDURE

1.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Disconnect the O48 smart door control receiver assembly connector.

(b) Measure the voltage and resistance and check for pulses according to the value(s) in the table below.

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

Standard Resistance:

Tester Connection	Condition	Specified Condition
H46-29 (E) - Body ground	Always	Below 1 Ω

Standard Voltage:

Tester Connection	Condition	Specified Condition
O47-11 (RDAM) - H46-29 (E)	Ignition switch off	11 to 14 V
O47-21 (RCO) - H46-29 (E)	Always	Below 1 V → 4.5 to 5.5 V pulse generation at regular intervals

REPLACE SMART DOOR CONTROL RECEIVER ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (SMART DOOR CONTROL RECEIVER ASSEMBLY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O47-11(RDAM) - O48-5 (DATA)	Always	Below 1 Ω
O47-21 (RCO) - O48-4 (+5)	Always	Below 1 Ω
O48-1 (GND) - Body ground	Always	Below 1 Ω
O48-5 (DATA) or O47-11 (RDAM) - Other terminals and body ground	Always	10 kΩ or higher
O48-4 (+5) or O47-21 (RCO) - Other terminals and body ground	Always	10 kΩ or higher

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

Diagnostic Trouble Code Chart

D..

No Answer-Back

DESCRIPTION In some cases, wireless door lock control functions are normal but the hazard warning light do not operate. In such cases, hazard warning light outputs from the main body ECU (multiplex network body ECU) may be malfunctioning...

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