Backup Boost Converter Circuit [09/2023 - ]: Procedure
- CHECK PROBLEM SYMPTOMS
- Determine the trouble area by referring to the table below.
Effect on Vehicle Trouble Area/Cause Fail-safe DTC Output Stop and start cancel indicator Symptom Proceed to When the engine is restarted by stop and start control:
The following symptoms may occur- Audio and visual system is reset
- The combination meter assembly fades out
- The steering wheel feels heavy when the engine is restarted*
*A DTC may be stored in the power steering system
Backup boost converter internal malfunction - Internal power source malfunction
- Internal power source overvoltage
- Duty error
- Communication cycle error
Stop and start control prohibited P323A-00
P323B-29
P323B-38Does not come on Converter output voltage cannot be boosted when the engine is restarted A Battery voltage drop Systems on the converter output side do not operate
B41 terminal: Tire pressure warning system
B43 terminal: Both of the following will not operate- Lighting system
- Digital rear-view mirror system
IG41 terminal: All of the following will not operate- Tire pressure warning system
- Parking support brake system
- Intuitive parking assist system
- Air conditioning system
EMOP terminal: The oil pump with solenoid assembly will not operateOvercurrent applied to an output terminal (output terminal relay circuit is shutoff) Stop and start control is prohibited
(Connected ECUs or sensors may detect power source malfunction DTCs)X087A Blinks Systems do not operate as power supply from the converter is cut off E Systems do not operate
(Due to converter input side malfunction)
IGP terminal: All of the following will not operate- Tire pressure warning system
- Meter / gauge system
- Parking support brake system
- Electronically controlled brake system
- Power steering system
- Intuitive parking assist system
- Air conditioning system
IGR terminal: -
ACC terminal: -Converter input circuit malfunction - Open or short to GND in IGR circuit
- Open or short to GND in IGP circuit
- Open or short to GND in ACC circuit
Stop and start control prohibited - Does not blink (Blinks when communication error DTCs are stored) Systems do not operate as power supply from the converter is cut off B Systems on the converter output side do not operate (varies depending on the malfunctioning relay circuit the converter detected)
IG12 terminal: The meter / gauge system will not operate
IG31 terminal: Both of the following will not operate- Electronically controlled brake system
- Power steering system
IG41 terminal: All of the following will not operate- Tire pressure warning system
- Parking support brake system
- Intuitive parking assist system
- Air conditioning system
B41 terminal: Tire pressure warning system
B43 terminal: Both of the following will not operate- Lighting system
- Digital rear-view mirror system
IL41 terminal: Both of the following will not operate- Lighting system
- Air conditioning system
Malfunction in circuits the converter supplies power to
(between the converter and ECUs or sensors)Related systems do not operate as the relay circuit in the converter is turned off - Does not blink (Blinks when communication error DTCs are stored) Systems do not operate as power supply from the converter is cut off B All of the following systems do not operate - Tire pressure warning system
- Audio and visual system
- Meter / gauge system
- Electronically controlled brake system
- Power steering system
- Air conditioning system
- Parking support brake system
- Digital rear-view mirror system
- Lighting system
- Intuitive parking assist system
- Open in BBC fuse circuit
- Short in converter circuit
- Backup boost converter malfunction
Stop and start control prohibited P0615-11 Does not blink (Due to disabled meter / gauge system) All systems that the converter supplies power to do not operate (see circuit diagram) A P323A-00
P323A-16
P323B-29
P323B-38The audio does not operate (until the ignition switch is turned off) Excessive audio volume Data List item "State of BBC" displays "BBC Overcurrent" while the circuit is protected The relay circuit in the converter is turned off to cut off power supply to the audio and visual system (Returns to normal when the ignition switch is turned off) - Does not blink If overcurrent is detected in the audio and visual system, system operation is disabled while the ignition switch is ON (Returns to normal when the ignition switch is turned off) C The external backup boost converter (eco run vehicle converter assembly) output side system does not operate - Audio and visual system
- Open in +BA NO. 2 fuse circuit
- Malfunction in circuits the converter supplies power to
- External backup boost converter (eco run vehicle converter assembly) malfunction
- - Does not blink All systems that the converter supplies power to do not operate (see circuit diagram) D - The combination meter assembly cannot be turned off (short between IG12 and +B)
Converter circuit malfunction - Short between IG12 and +B
- - Does not blink The converter cannot shut off the power source when the ignition switch is turned off B - Ignition switch cannot be turned off from ACC (short between ACC and +B)
- Ignition switch cannot be turned off from ON (short between IGP or IGR and +B)
Engine stop and start ECU power source circuit malfunction - Short between ACC and +B
- Short between IGP and +B
- Short between IGR and +B
- - Does not blink - Ignition switch does not turn ACC
- Ignition switch cannot be turned off
B Result
Proceed to A B C D E
Result:
A
GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [09/2023 - ]
Result:
C
See step 5
Result:
D
See step 7
Result:
E
See step 13
Result:
B
See step 2
- Determine the trouble area by referring to the table below.
- CHECK ENGINE STOP AND START ECU (POWER SOURCE CIRCUIT)
- Disconnect the engine stop and start ECU connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition B24-1 (BIN2) - Body ground Always 9.5 to 14 V B24-3 (BIN1) - Body ground Always 9.5 to 14 V - Turn the ignition switch to ACC.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition D26-19 (ACC) - Body ground Ignition switch ACC 9.5 to 14 V - Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition D26-21 (IGR) - Body ground Ignition switch ON 9.5 to 14 V D26-18 (IGP) - Body ground Ignition switch ON 9.5 to 14 V - Turn the headlight dimmer switch (light control switch) to the tail or head position.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition D26-20 (ILL) - Body ground Headlight dimmer switch (light control switch) in tail or head position 9.5 to 14 V - Turn the headlight dimmer switch (light control switch) to off.
- Turn the ignition switch off.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition D26-21 (IGR) - Body ground Ignition switch off 0 to 1 V D26-19 (ACC) - Body ground Ignition switch off 0 to 1 V D26-18 (IGP) - Body ground Ignition switch off 0 to 1 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - EACH ECU OR SENSOR)
- Disconnect the connector from the corresponding system ECU/sensor.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
TIRE PRESSURE WARNING ECU AND RECEIVERTester Connection Condition Specified Condition D26-3 (IG41) - J4-1 (IG) Always Below 1 Ω D26-2 (B41) - J4-7 (+B) Always Below 1 Ω D26-3 (IG41) - Body ground Always 10 kΩ or higher J4-1 (IG) - Body ground Always 10 kΩ or higher D26-2 (B41) - Body ground Always 10 kΩ or higher J4-7 (+B) - Body ground Always 10 kΩ or higher METER MIRROR SUB-ASSEMBLY (W/ HEADUP DISPLAY)Tester Connection Condition Specified Condition D26-10 (IG12) - D11-10 (IG) Always Below 1 Ω D26-10 (IG12) - Body ground Always 10 kΩ or higher D11-10 (IG) - Body ground Always 10 kΩ or higher CLEARANCE WARNING ECU ASSEMBLYTester Connection Condition Specified Condition D26-3 (IG41) - B32-1 (IG) Always Below 1 Ω D26-3 (IG41) - Body ground Always 10 kΩ or higher B32-1 (IG) - Body ground Always 10 kΩ or higher INNER REAR VIEW MIRROR ASSEMBLYTester Connection Condition Specified Condition D26-11 (B43) - K3-6 (+B) Always Below 1 Ω D26-11 (B43) - Body ground Always 10 kΩ or higher K3-6 (+B) - Body ground Always 10 kΩ or higher *: w/o Digital Inner Mirror System
POWER STEERING ECU (RACK AND PINION POWER STEERING GEAR ASSEMBLY)Tester Connection Condition Specified Condition D26-23 (IG31) - C35-4 (IG) Always Below 1 Ω D26-23 (IG31) - Body ground Always 10 kΩ or higher C35-4 (IG) - Body ground Always 10 kΩ or higher BRAKE ACTUATOR ASSEMBLYTester Connection Condition Specified Condition D26-23 (IG31) - B31-45 (IGR) Always Below 1 Ω D26-23 (IG31) - Body ground Always 10 kΩ or higher B31-45 (IGR) - Body ground Always 10 kΩ or higher COMBINATION METER ASSEMBLYTester Connection Condition Specified Condition D26-10 (IG12) - D16-6 (IG+) Always Below 1 Ω D26-10 (IG12) - Body ground Always 10 kΩ or higher D16-6 (IG+) - Body ground Always 10 kΩ or higher NO. 2 AIR CONDITIONING CONTROL ASSEMBLYTester Connection Condition Specified Condition D26-25 (IL41) - D110-10 (ILL+) Always Below 1 Ω D26-3 (IG41) - D110-9 (IG) Always Below 1 Ω D26-25 (IL41) - Body ground Always 10 kΩ or higher D26-3 (IG41) - Body ground Always 10 kΩ or higher D110-10 (ILL+) - Body ground Always 10 kΩ or higher D110-9 (IG) - Body ground Always 10 kΩ or higher DOME CUT NO. 2 RELAYTester Connection Condition Specified Condition D26-11 (B43) - 5 (DOME CUT NO. 2 relay) Always Below 1 Ω D26-11 (B43) - Body ground Always 10 kΩ or higher 5 (DOME CUT NO. 2 relay) - Body ground Always 10 kΩ or higher ROOM LIGHT CONTROL RELAYTester Connection Condition Specified Condition D26-11 (B43) - D54-1 (+B) Always Below 1 Ω D54-1 (+B) - Body ground Always 10 kΩ or higher D26-11 (B43) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 4
- CHECK ENGINE STOP AND START ECU (EACH ECU OR SENSOR POWER SOURCE CIRCUIT)
- Disconnect the connector from the corresponding system ECU/sensor.
- Measure the voltage according to the value(s) in the table below.
HINT:
Measure the voltage at the corresponding terminals.
Standard Voltage
Tester Connection Condition Specified Condition J4-7 (+B) - Body ground Always 10.5 to 16 V K3-6 (+B) - Body ground Always 10.5 to 16 V 5 (DOME CUT NO. 2 relay) - Body ground Always 10.5 to 16 V - Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
HINT:
Measure the voltage at the corresponding terminals.
Standard Voltage
Tester Connection Switch Condition Specified Condition B31-45 (IGR) - Body ground Ignition switch ON 10.5 to 16 V C35-4 (IG) - Body ground Ignition switch ON 10.5 to 16 V D11-10 (IG) - Body ground Ignition switch ON 10.5 to 16 V J4-1 (IG) - Body ground Ignition switch ON 10.5 to 16 V B32-1 (IG)*1 - Body ground Ignition switch ON 10.5 to 16 V D16-6 (IG+) - Body ground Ignition switch ON 10.5 to 16 V D110-9 (IG) - Body ground Ignition switch ON 10.5 to 16 V *1: w/ Parking Support Brake System
- Turn the light control switch to the tail or head position.
- Measure the voltage according to the value(s) in the table below.
HINT:
Measure the voltage at the corresponding terminals.
Standard Voltage
Tester Connection Switch Condition Specified Condition D110-10 (ILL+) - Body ground Light control switch in tail or head position 10.5 to 16 V Result
Proceed to OK NG
Result:
OK
CHECK POWER SOURCE CIRCUIT (POWER SOURCE CIRCUIT OF RELATED SYSTEM)
Result:
NG
REPLACE ENGINE STOP AND START ECU. Refer to REMOVAL [09/2023 - ]
- CHECK AUDIO AND VISUAL SYSTEM
- Turn the ignition switch off and wait for 1 minute.
- Turn the ignition switch to ON.
- Lower the audio volume.
- Check if the audio and visual system operates normally.
OK
Audio and visual system operates normally.
Result
Proceed to OK NG
Result:
OK
END
Result:
NG
See step 6
- CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - STEREO COMPONENT AMPLIFIER ASSEMBLY)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Disconnect the stereo component amplifier assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B6-5 (BO1), J17-1 (+B) or J17-16 (+B2) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
GO TO AUDIO AND VISUAL SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - 12/2023] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (BIN TERMINAL POWER SOURCE CIRCUIT)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition B6-11 (BIN) - Body ground Always 9.5 to 14 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - BATTERY)
Result:
OK
See step 8
- CHECK HARNESS AND CONNECTOR (ACC TERMINAL POWER SOURCE CIRCUIT)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Turn the ignition switch to ACC.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition B6-3 (ACC) - Body ground Ignition switch ACC 9.5 to 14 V - Turn the ignition switch off.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition B6-3 (ACC) - Body ground Ignition switch off 0 to 1 V Result
Proceed to OK NG
Result:
NG
See step 12
Result:
OK
See step 9
- CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - BODY GROUND)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B6-6 (GND) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 10
- CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - STEREO COMPONENT AMPLIFIER ASSEMBLY)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Disconnect the stereo component amplifier assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B6-5 (BO1) - J17-1 (+B) Always Below 1 Ω B6-5 (BO1) - J17-16 (+B2) Always Below 1 Ω B6-5 (BO1)or J17-1 (+B) or J17-16 (+B2) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 11
- CHECK EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) (OUTPUT VOLTAGE FOR EACH SYSTEM)
- Disconnect the stereo component amplifier assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition J17-1 (+B) - Body ground Always 10.5 to 16 V J17-16 (+B2) - Body ground Always 10.5 to 16 V Result
Proceed to OK NG
Result:
OK
GO TO AUDIO AND VISUAL SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - 12/2023] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2023 - ]
Result:
NG
REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY). Refer to REMOVAL [09/2023 - ]
- CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - POWER DISTRIBUTION BOX ASSEMBLY)
- Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
- Disconnect the power distribution box assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B6-3 (ACC) - J48-11 Always Below 1 Ω B6-3 (ACC) or J48-11 - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE POWER DISTRIBUTION BOX ASSEMBLY. Refer to PROCEDURE - Step 5
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BBC NO. 1, BBC NO. 2 FUSES)
- Disconnect the engine stop and start ECU connector.
- Remove the BBC NO. 1 and BBC NO. 2 fuses from the No. 1 engine room relay block and No. 1 junction block assembly.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B24-1 (BIN2) - BBC NO. 2 fuse terminal 2 Always Below 1 Ω B24-3 (BIN1) - BBC NO. 1 fuse terminal 2 Always Below 1 Ω B24-1 (BIN2) - Body ground Always 10 kΩ or higher BBC NO. 2 fuse terminal 2 - Body ground Always 10 kΩ or higher B24-3 (BIN1) - Body ground Always 10 kΩ or higher BBC NO. 1 fuse terminal 2 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 14
- CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - EACH ECU OR SENSOR)
- Disconnect the engine stop and start ECU connector.
- Disconnect the NO. 2 air conditioning control assembly connector.
- Disconnect the clearance warning ECU assembly connector. (w/ Parking Support Brake System)
- Disconnect the room light control relay connector.
- Disconnect the DOME CUT NO. 2 relay connector.
- Disconnect the tire pressure warning ECU and receiver connector.
- Disconnect the inner rear view mirror assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition D26-3 (IG41) - B32-1 (IG) Always Below 1 Ω D26-3 (IG41) - D110-9 (IG) Always Below 1 Ω D26-3 (IG41) - J4-1 (IG) Always Below 1 Ω D26-2 (B41) - J4-7 (+B) Always Below 1 Ω D26-11 (B43) - 5 (DOME CUT NO. 2 relay) Always Below 1 Ω D26-11 (B43) - K3-6 (+B) Always Below 1 Ω D26-11 (B43) - D54-1 (+B) Always Below 1 Ω D26-3 (IG41) - Body ground Always 10 kΩ or higher D26-2 (B41) - Body ground Always 10 kΩ or higher D26-11 (B43) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 15
- CHECK ENGINE STOP AND START ECU
- Disconnect the engine stop and start ECU connectors.
*a Component without harness connected
(Engine Stop and Start ECU)- - - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition D26-3 (IG41) - B25-6 (DGND) Always 10 kΩ or higher D26-2 (B41) - B25-6 (DGND) Always 10 kΩ or higher D26-11 (B43) - B25-6 (DGND) Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPLACE ENGINE STOP AND START ECU. Refer to REMOVAL [09/2023 - ]
Result:
OK
See step 16
- Disconnect the engine stop and start ECU connectors.
- CHECK VEHICLE CONDITION (B41, B43 AND IG41 CIRCUIT)
- Check that additional devices installed to the vehicle (aftermarket audio system, etc.) are not connected to the B41, B43 or IG41 terminal circuit of the engine stop and start ECU.
Result
Result Proceed to Load from an additional device installed to the vehicle (aftermarket audio system, etc.) is not applied. A Load from an additional device installed to the vehicle (aftermarket audio system, etc.) is applied. B
Result:
A
TROUBLESHOOT ECUS CONNECTED TO TERMINALS B41, B43 AND IG41
Result:
B
END (REMOVE ADDITIONAL DEVICE)
- Check that additional devices installed to the vehicle (aftermarket audio system, etc.) are not connected to the B41, B43 or IG41 terminal circuit of the engine stop and start ECU.