STOP AND START: STOP AND START SYSTEM: Backup Boost Converter Circuit; 2023 MY RAV4 [10/2022

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM1000000025YAB
Model Year Start: 2023	Model: RAV4	Prod Date Range: [10/2022 - 10/2023]
Title: STOP AND START: STOP AND START SYSTEM: Backup Boost Converter Circuit; 2023 MY RAV4 [10/2022 - 10/2023]

Backup Boost Converter Circuit

DESCRIPTION

A backup boost converter is built into the engine stop and start ECU. The backup boost converter helps maintain the power source voltage when the engine is restarted by stop and start control.

This prevents various functions such as the audio and visual system from malfunctioning if the power source voltage drops due to the battery voltage dropping when the engine is restarted by stop and start control.

If any DTCs are output, troubleshoot the DTCs first.

HINT:

A relay function and fuse function are provided in the backup boost converter.

If there is a malfunction in any of the electrical system circuits connected to the backup boost converter, the fuse and relay functions shut off the malfunctioning circuit to protect other circuits (remains shut off until next trip).

When the electrical system circuit is shut off, power to the circuit is cut off, causing any systems connected to the circuit to be disabled.

The fuse function is reset* when the ignition switch is turned off. If the malfunction still exists in the electrical system circuit that has been shut off by the relay function, it will be shut off again by the relay and fuse functions the next time the ignition switch is turned to ON.

*: A semiconductor fuse self resets according to electric signal.

The backup boost converter supplies power to:

Dynamic radar cruise control system
Tire pressure warning system
Vehicle stability control system
Power steering system
Audio and visual system
Blind spot monitor system
Telematics system
CAN communication system
Meter / gauge system
Air conditioning system
Intuitive parking assist system
Digital rear-view mirror system

WIRING DIAGRAM

Refer to DTC P323A19.

Click here

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.
Click here
After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
Click here
After replacing the engine stop and start ECU or airbag ECU assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.
Click here
When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK PROBLEM SYMPTOMS

(a) 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*	Backup boost converter internal malfunction Internal power source malfunction Internal power source overvoltage CPU duty malfunction Communication cycle error	Stop and start control prohibited	P323A00 P323AA2 P323B29 P323B38	Blinks	Systems stop operating during engine restart as the backup boost converter output voltage cannot be boosted	A
	Battery voltage drop	Stop and start control prohibited	P323A00 P323AA2 P323B29 P323B38	Blinks		A
Systems on the converter output side do not operate B41 terminal: Tire pressure warning system will not operate B42 terminal: Audio and visual system will not operate B43 terminal: All of the following will not operate Digital rear-view mirror system IG41 terminal: All of the following will not operate Tire pressure warning system Blind spot monitor system CAN communication system Air conditioning system Intuitive parking assist system EMOP terminal: The oil pump with solenoid assembly will not operate	Overcurrent 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)	P323A19	Blinks	Systems do not operate as power supply from the converter is cut off	A
Systems do not operate (Due to converter input side malfunction) IG1 terminal: All of the following will not operate Tire pressure warning system Vehicle stability control system Power steering system Blind spot monitor system CAN communication system Air conditioning system IG2 terminal: Both of the following will not operate Meter / gauge system Telematics system ACC terminal: The audio and visual system will not operate	Converter input circuit malfunction Open or short to GND in IG1 circuit Open or short to GND in IG2 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) AC41 terminal: The audio and visual system will not operate IG11 terminal: The power steering system will not operate IG12 terminal: The meter / gauge system will not operate IG13 terminal: Both of the following will not operate Vehicle stability control system Power steering system IG31 terminal: The vehicle stability control system will not operate IG41 terminal: All of the following will not operate Tire pressure warning system Blind spot monitor system CAN communication system Air conditioning system Intuitive parking assist system B12 terminal: The telematics system will not operate B41 terminal: Tire pressure warning system will not operate B42 terminal: Audio and visual system will not operate B43 terminal: All of the following will not operate Digital rear-view mirror 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 Vehicle stability control system Power steering system Audio and visual system Blind spot monitor system CAN communication system Meter / gauge system Air conditioning system Digital rear-view mirror system	Open in BBC fuse circuit Short in converter circuit Backup boost converter malfunction	Stop and start control prohibited	P061519	Does not blink (Due to disabled meter / gauge system)	All systems that the converter supplies power to do not operate (see circuit diagram)	A
		Stop and start control prohibited	P30DF62 P30EF4B P323A00 P323A16 P323AA2 P323B29 P323B38	Does not blink (Due to disabled meter / gauge system)		A
The 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 combination meter assembly cannot be turned off (short between IG12 and +B) Communication error DTCs may be stored due to short between AC41 and +B Communication error DTCs may be stored due to short between AC42 and +B HINT: Varies depending on the number of times an open occurs in the +B circuit	Converter circuit malfunction Short between IG12 and +B Short between AC41 and +B Short between AC42 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 IG (short between IG1 or IG2 and +B)	Engine stop and start ECU power source circuit malfunction Short between ACC and +B Short between IG1 and +B Short between IG2 and +B	-	-	Does not blink	Ignition switch cannot be turned off	B

*: A DTC may be stored in the power steering system

GO TO DIAGNOSTIC TROUBLE CODE CHART

GO TO STEP 7

2.	CHECK HARNESS AND CONNECTOR (BIN1 AND BIN2 TERMINALS POWER SOURCE CIRCUIT)

*a	Front view of wire harness connector (to Engine Stop and Start ECU)

(a) Disconnect the engine stop and start ECU connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A33-1 (BIN2) - Body ground	Always	9.5 to 14 V
A33-3 (BIN1) - Body ground	Always	9.5 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE STOP AND START ECU - BATTERY)

3.	CHECK HARNESS AND CONNECTOR (IG1 AND ACC TERMINALS POWER SOURCE CIRCUIT)

*a	Front view of wire harness connector (to Engine Stop and Start ECU)

(a) Disconnect the engine stop and start ECU connector.

(b) Turn the Ignition switch to ACC.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A32-19 (ACC) - Body ground	Ignition switch ACC	9.5 to 14 V

(d) Turn the ignition switch to ON.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A32-21 (IG1) - Body ground	Ignition switch ON	9.5 to 14 V

(f) Turn the ignition switch to off.

(g) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A32-19 (ACC) - Body ground	ignition switch off	0 to 1 V
A32-21 (IG1) - Body ground	ignition switch off	0 to 1 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE STOP AND START ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1 NO. 1 OR ACC RELAY))

4.	CHECK HARNESS AND CONNECTOR (+B TERMINAL POWER SOURCE CIRCUIT)

*a	Front view of wire harness connector (to Engine Stop and Start ECU)

(a) Disconnect the engine stop and start ECU connector.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A34-1 (+B) - Body ground	Ignition switch ON	9.5 to 14 V

(d) Turn the ignition switch to off.

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A34-1 (+B) - Body ground	Ignition switch off	0 to 1 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE STOP AND START ECU - EFI-MAIN NO. 1 RELAY)

5.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - EACH ECU OR SENSOR)

(a) Disconnect the connector from the corresponding system ECU/sensor.

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

Standard Resistance:

Power Steering ECU (Rack and Pinion Power Steering Gear Assembly)

Tester Connection	Condition	Specified Condition
A32-6 (IG11) - C54-4 (IG)	Always	Below 1 Ω
A32-6 (IG11) or C54-4 (IG) - Body ground and other terminals	Always	10 kΩ or higher

Combination Meter Assembly

Tester Connection

Condition

Specified Condition

A32-10 (IG12) - G18-38 (IG+)*3

A32-10 (IG12) - G141-6 (IG+)*4

Always

Below 1 Ω

A32-10 (IG12) or G18-38 (IG+)*3 - Body ground and other terminals

A32-10 (IG12) or G141-6 (IG+)*4 - Body ground and other terminals

Always

10 kΩ or higher

Telematics Transceiver Assembly

Tester Connection	Condition	Specified Condition
A32-26 (IG13) - G131-19 (IG2)	Always	Below 1 Ω
A32-16 (B12) - G131-1 (+B)	Always	Below 1 Ω
A32-26 (IG13) or G131-19 (IG2) - Body ground and other terminals	Always	10 kΩ or higher
A32-16 (B12) or G131-1 (+B) - Body ground and other terminals	Always	10 kΩ or higher

Radio and Display Receiver Assembly (w/ Display Audio System)

Tester Connection	Condition	Specified Condition
A32-12 (B42) - G3-4 (+B1)	Always	Below 1 Ω
A32-24 (AC41) - G3-16 (ACC1)	Always	Below 1 Ω
A32-12 (B42) or G3-4 (+B1) - Body ground and other terminals	Always	10 kΩ or higher
A32-24 (AC41) or G3-16 (ACC1) - Body ground and other terminals	Always	10 kΩ or higher

Electrical Key and Tire Pressure Monitoring System Receiver Assembly (w/ Tire Pressure Warning System)

Tester Connection	Condition	Specified Condition
A32-2 (B41) - M8-7 (+B)	Always	Below 1 Ω
A32-3 (IG41) - M8-1 (IG)	Always	Below 1 Ω
A32-2 (B41) or M8-7 (+B) - Body ground and other terminals	Always	10 kΩ or higher
A32-3 (IG41) or M8-1 (IG) - Body ground and other terminals	Always	10 kΩ or higher

Central Gateway ECU (Network Gateway ECU)

Tester Connection	Condition	Specified Condition
A32-3 (IG41) - G72-11 (IG1)	Always	Below 1 Ω
A32-3 (IG41) or G72-11 (IG1) - Body ground and other terminals	Always	10 kΩ or higher

Millimeter Wave Radar Sensor Assembly (w/ Dynamic Radar Cruise Control System)

Tester Connection	Condition	Specified Condition
A32-3 (IG41) - B9-8 (IGB)	Always	Below 1 Ω
A32-3 (IG41) or B9-8 (IGB) - Body ground and other terminals	Always	10 kΩ or higher

Blind Spot Monitor Sensor LH

Tester Connection	Condition	Specified Condition
A32-3 (IG41) - Q1-5 (BLB)	Always	Below 1 Ω
A32-3 (IG41) or Q1-5 (BLB) - Body ground and other terminals	Always	10 kΩ or higher

Blind Spot Monitor Sensor RH

Tester Connection	Condition	Specified Condition
A32-3 (IG41) - Q13-5 (BRB)	Always	Below 1 Ω
A32-3 (IG41) or Q13-5 (BRB) - Body ground and other terminals	Always	10 kΩ or higher

Air Conditioning Control Assembly

Tester Connection	Condition	Specified Condition
A32-3 (IG41) - G24-9 (IG+)	Always	Below 1 Ω
A32-25 (IL41) - G24-8 (ILL+)	Always	Below 1 Ω
A32-3 (IG41) or G24-9 (IG+) - Body ground and other terminals	Always	10 kΩ or higher
A32-25 (IL41) or G24-8 (ILL+) - Body ground and other terminals	Always	10 kΩ or higher

Skid Control ECU (Brake Actuator Assembly)

Tester Connection	Condition	Specified Condition
A32-1 (IG31) - A39-36 (IG1)	Always	Below 1 Ω
A32-1 (IG31) or A39-36 (IG1) - Body ground and other terminals	Always	10 kΩ or higher

Steering Sensor

Tester Connection	Condition	Specified Condition
A32-1 (IG31) - G68-9 (IG1)	Always	Below 1 Ω
A32-1 (IG31) or G68-9 (IG1) - Body ground and other terminals	Always	10 kΩ or higher

Clearance Warning ECU Assembly

Tester Connection

Condition

Specified Condition

A32-1 (IG41) - G25-1 (IG)*1

A32-3 (IG41) - H4-1 (IG)*2

Always

Below 1 Ω

A32-3 (IG41) or G25-1 (IG)*1 - Body ground and other terminals

A32-3 (IG41) or H4-1 (IG)*2 - Body ground and other terminals

Always

10 kΩ or higher

Inner Rear-view Mirror Assembly (w/ Digital Rear-view Mirror System)

Tester Connection	Condition	Specified Condition
A32-11 (B43) - P1-6 (+B)	Always	Below 1 Ω
A32-11 (IG11) or P1-6 (IG) - Body ground and other terminals	Always	10 kΩ or higher

*1: except TMC Made
*2: for TMC Made
*3: except 12.3 Inch Multi Information Display
*4: for 12.3 Inch Multi Information Display

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK ENGINE STOP AND START ECU (OUTPUT VOLTAGE FOR EACH ECU OR SENSOR)

(a) Disconnect the connector from the corresponding system ECU/sensor.

(b) 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
G131-1 (+B) - Body ground	Always	10.5 to 16 V
G3-4 (+B1) - Body ground*1	Always	10.5 to 16 V
M8-7 (+B) - Body ground*2	Always	10.5 to 16 V
P1-6 (+B) - Body ground*3	Always	10.5 to 16 V

*1: w/ Display Audio System
*2: w/ Tire Pressure Warning System
*3: w/ Digital Rear-view Mirror System

(d) 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
G3-16 (ACC1) - Body ground*	Ignition switch ACC	10.5 to 16 V

*: w/ Display Audio System

(e) Turn the ignition switch to ON.

(f) 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
C54-4 (IG) - Body ground	Ignition switch ON	10.5 to 16 V
G18-38 (IG+)*3 - Body ground	Ignition switch ON	10.5 to 16 V
G141-6 (IG+)*4 - Body ground	Ignition switch ON	10.5 to 16 V
G131-18 (IG2) - Body ground	Ignition switch ON	10.5 to 16 V
G72-11 (IG1) - Body ground	Ignition switch ON	10.5 to 16 V
B9-8 (IGB) - Body ground	Ignition switch ON	10.5 to 16 V
Q1-5 (BLB) - Body ground	Ignition switch ON	10.5 to 16 V
Q13-5 (BRB) - Body ground	Ignition switch ON	10.5 to 16 V
G24-9 (IG+) - Body ground	Ignition switch ON	10.5 to 16 V
M8-1 (IG) - Body ground	Ignition switch ON	10.5 to 16 V
A39-36 (IG1) - Body ground	Ignition switch ON	10.5 to 16 V
G68-9 (IG1) - Body ground	Ignition switch ON	10.5 to 16 V
G25-1 (IG1)*1 - Body ground	Ignition switch ON	10.5 to 16 V
H4-1 (IG1)*2 - Body ground	Ignition switch ON	10.5 to 16 V

*1: except TMC Made
*2: for TMC Made
*3: except 12.3 Inch Multi Information Display
*4: for 12.3 Inch Multi Information Display

(g) Turn the headlight dimmer switch (light control switch) to the tail or head position.

(h) 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
G24-8 (ILL+) - Body ground	Headlight dimmer switch (light control switch) in tail or head position	10.5 to 16 V

CHECK POWER SOURCE CIRCUIT (POWER SOURCE CIRCUIT OF RELATED SYSTEM)

REPLACE ENGINE STOP AND START ECU

7.	CHECK AUDIO AND VISUAL SYSTEM

(a) Turn the ignition switch off and wait for 1 minute.

(b) Turn the ignition switch to ON.

(d) Check if the audio and visual system operates normally.

OK:

Audio and visual system operates normally.

END

8.	CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - RADIO AND DISPLAY RECEIVER ASSEMBLY)

(a) Disconnect the engine stop and start ECU connector.

(b) Disconnect the radio and display receiver assembly connector. (w/ Display Audio System)

Standard Resistance:

Tester Connection	Condition	Specified Condition
A32-12 (B42) or G3-4 (+B1) - Body ground	Always	10 kΩ or higher

GO TO AUDIO AND VISUAL SYSTEM (W/ DISPLAY AUDIO SYSTEM)

REPAIR OR REPLACE HARNESS OR CONNECTOR