Toyota Yaris: Smart Key System (for Start Function) / Front Floor Electrical Key Oscillator Circuit Open (B27A513)

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System (for Start Function) / Front Floor Electrical Key Oscillator Circuit Open (B27A513)

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the No. 1 indoor electrical key antenna assembly (front floor). For the No. 1 indoor electrical key antenna assembly (front floor) to detect when the electrical key transmitter sub-assembly is in the cabin, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the vehicle. DTC B27A513 is stored by the certification ECU (smart key ECU assembly) when an open is detected between the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (front floor) (between terminals CLG5 and ANTE5, or terminals CG5B and CLGB).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B27A513	Front Floor Electrical Key Oscillator Circuit Open	An open is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (front floor) (CLG5 - ANTE5, CG5B - CLGB) (1 trip detection logic*).	Certification ECU (smart key ECU assembly) No. 1 indoor electrical key antenna assembly (front floor) Wire harness or connector	Any time

*: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
When electrical key transmitter sub-assembly is in front seat area: Power source mode does not change when engine switch pressed Electrical key transmitter sub-assembly locked inside vehicle	-

Related Data List and Active Test

DTC No.	Data List and Active Test
B27A513	Key diagnostic mode can be used to perform troubleshooting

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 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.
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Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
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After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	CHECK CONNECTOR CONNECTION

(a) Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (front floor).

OK:

Connectors are properly connected.

CONNECT CONNECTORS PROPERLY

2.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR))

(a) Disconnect the H46 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the H70 No. 1 indoor electrical key antenna assembly (front floor) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
H46-4 (CLG5) - H70-1 (ANTE5)	Always	Below 1 Ω
H46-5 (CG5B) - H70-2 (CLGB)	Always	Below 1 Ω

(d) Reconnect the H46 certification ECU (smart key ECU assembly) connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR))

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

Waveform

For 30 seconds after any door closed

After 30 seconds or more have elapsed since any door closed

(a) Using an oscilloscope, check the waveform.

OK:

Tester Connection	Condition	Tool Setting	Specified Condition
H46-4 (CLG5) - H46-29 (E)	Procedure: Ignition switch off Electrical key transmitter sub-assembly not inside vehicle Within 30 seconds of closing any door	5 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)
H46-5 (CG5B) - H46-29 (E)	Procedure: Ignition switch off Electrical key transmitter sub-assembly not inside vehicle Within 30 seconds of closing any door	5 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)

Tester Connection

Condition

Tool Setting

Specified Condition

H46-4 (CLG5) - H46-29 (E)

Procedure:

Ignition switch off
Electrical key transmitter sub-assembly not inside vehicle
Within 30 seconds of closing any door

5 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

H46-5 (CG5B) - H46-29 (E)

Procedure:

Ignition switch off
Electrical key transmitter sub-assembly not inside vehicle
Within 30 seconds of closing any door

5 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Steering Lock Confirmation Signal Circuit Voltage Out of Range (B279F1C)

DESCRIPTION This DTC is stored when the SLA input (the steering lock motor activation permission signal) sent directly from the certification ECU (smart key ECU assembly) to the steering lock ECU (steering lock actuator or upper bracket assembly) is determined to be abnormal...

Crankshaft Position Sensor "A" Signal Compare Failure (P033562)

DESCRIPTION These DTCs are stored when the engine speed signal sent by the ECM via direct line and the engine speed signal sent via CAN communication do not match...

Other information:

Toyota Yaris XP210 (2020-2025) Reapir and Service Manual: Diagnostic Trouble Code Chart

DIAGNOSTIC TROUBLE CODE CHART SFI System DTC No. Detection Item MIL Note Link P001013 A Camshaft Position Actuator Bank 1 Circuit Open Comes on SAE: P0010 P001100 Camshaft Position "A" - Timing Over-Advanced or System Performance Bank 1 Comes on SAE: P0011 P001200 Camshaft Position "A" - Timing Over-Retarded Bank 1 Comes on SAE: P0012 P001313 Camshaft Position "B" - Actuator Bank 1 Circuit Open Comes on SAE: P0013 P001400 Camshaft Position "B" - Timing Over-Advanced or System Performance Bank 1 Comes on SAE: P0014 P001500 Camshaft Position "B" - Timing Over-Retarded Bank 1 Comes on SAE: P0015 P001600 Crankshaft Position - Camshaft Position Correlation Bank 1 Sensor A Comes on SAE: P0016 P001700 Crankshaft Position - Camshaft Position Correlation Bank 1 Sensor B Comes on SAE: P0017 P003012 HO2S Heater Control Bank 1 Sensor 1 Circuit Short to Battery Comes on SAE: P0032 P003013 HO2S Heater Control Bank 1 Sensor 1 Circuit Open Comes on SAE: P0031 P003312 Turbocharger / Supercharger Bypass Valve "A" Control Circuit Short to Battery - SAE: P0035 P003314 Turbocharger / Supercharger Bypass Valve "A" Control Circuit Short to Ground or Open - SAE: P0034 P003612 HO2S Heater Control Circuit Bank 1 Sensor 2 Circuit Short to Battery Comes on SAE: P0038 P003613 A/F (O2) Heater Control Circuit Bank 1 Sensor 2 Circuit Open Comes on SAE: P0037 P006D62 Barometric Pressure - Turbocharger/Supercharger Inlet Pressure Correlation Bank 1 Signal Compare Failure - SAE: P006D P007A11 Charge Air Cooler Temperature Sensor Bank 1 Circuit Short to Ground - SAE: P007C P007A15 Charge Air Cooler Temperature Sensor Bank 1 Circuit Short to Battery or Open - SAE: P007D P008700 Fuel Rail / System Pressure - Too Low Comes on SAE: P0087 P008800 Fuel Rail / System Pressure - Too High Comes on SAE: P0088 P008A00 Low Pressure Fuel System Pressure - Too Low - SAE: P008A P008B00 Low Pressure Fuel System Pressure - Too High - SAE: P008B P00CF62 Barometric Pressure - Turbocharger / Supercharger Boost Sensor "A" Signal Compare Failure Comes on SAE: P00CF P010012 Mass or Volume Air Flow Sensor "A" Circuit Short to Battery Comes on SAE: P0103 P010014 Mass or Volume Air Flow Sensor "A" Circuit Short to Ground or Open Comes on SAE: P0102 P010511 Manifold Absolute Pressure / Barometric Pressure Sensor Circuit Short to Ground Comes on SAE: P0107 P010515 Manifold Absolute Pressure / Barometric Pressure Sensor Circuit Short to Battery or Open Comes on SAE: P0108 P011011 Intake Air Temperature Sensor 1 Bank 1 Circuit Short to Ground Comes on SAE: P0112 P011015 Intake Air Temperature Sensor 1 Bank 1 Circuit Short to Battery or Open Comes on SAE: P0113 P011511 Engine Coolant Temperature Sensor 1 Circuit Short to Ground Comes on SAE: P0117 P011515 Engine Coolant Temperature Sensor 1 Circuit Short to Battery or Open Comes on SAE: P0118 P01152A Engine Coolant Temperature Sensor 1 Signal Stuck in Range Comes on SAE: P0116 P012011 Throttle / Pedal Position Sensor / Switch "A" Circuit Short to Ground Comes on SAE: P0122 P012015 Throttle / Pedal Position Sensor / Switch "A" Circuit Short to Battery or Open Comes on SAE: P0123 P01201C Throttle / Pedal Position Sensor / Switch "A" Circuit Voltage Out of Range Comes on SAE: P0121 P012A11 Turbocharger/Supercharger Inlet Pressure Sensor "A" Circuit Low Circuit Short to Ground - SAE: P012C P012A15 Turbocharger/Supercharger Inlet Pressure Sensor "A" Circuit High Circuit Short to Battery or Open - SAE: P012D P013616 A/F (O2) Sensor Circuit Bank 1 Sensor 2 Circuit Current (Voltage) Below Threshold Comes on SAE: P0136 P017100 System Too Lean Bank 1 Comes on SAE: P0171 P017200 System Too Rich Bank 1 Comes on SAE: P0172 P019011 Fuel Rail Pressure Sensor "A" Circuit Short to Ground Comes on SAE: P0192 P019015 Fuel Rail Pressure Sensor "A" Circuit Short to Battery or Open Comes on SAE: P0193 P019511 Engine Oil Temperature Sensor Circuit Short to Ground - SAE: P0197 P019515 Engine Oil Temperature Sensor Circuit Short to Battery or Open - SAE: P0198 P020113 Cylinder 1 Injector "A" Circuit Open Comes on SAE: P0201 P020213 Cylinder 2 Injector "A" Circuit Open Comes on SAE: P0202 P020313 Cylinder 3 Injector "A" Circuit Open Comes on SAE: P0203 P022011 Throttle/Pedal Position Sensor/Switch "B" Circuit Short to Ground Comes on SAE: P0222 P022015 Throttle/Pedal Position Sensor/Switch "B" Circuit Short to Battery or Open Comes on SAE: P0223 P023400 Turbocharger/Supercharger "A" Overboost Condition - SAE: P0234 P023511 Turbocharger/Supercharger Boost Sensor "A" Circuit Short to Ground Comes on SAE: P0237 P023515 Turbocharger/Supercharger Boost Sensor "A" Circuit Short to Battery or Open Comes on SAE: P0238 P02351C Turbocharger/Supercharger Boost Sensor "A" Circuit Voltage Out of Range - SAE: P0236 P024313 Turbocharger/Supercharger Wastegate Solenoid "A" Circuit Open Does not come on SAE: P0243 P030000 Random/Multiple Cylinder Misfire Detected Comes on/Blinks* *: The MIL flashes when a catalyst-damaging misfire is detected...

Toyota Yaris XP210 (2020-2025) Owner's Manual: Plastic Part Maintenance

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