Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM1000000025YAA
Model Year Start: 2023 Model: RAV4 Prod Date Range: [10/2022 - 10/2023]
Title: STOP AND START: STOP AND START SYSTEM: P323A19; Backup Boost Converter "A" Circuit Current Above Threshold; 2023 MY RAV4 [10/2022 - 10/2023]

DTC

P323A19

Backup Boost Converter "A" Circuit Current Above Threshold

DESCRIPTION

A backup boost converter is built into the engine stop and start ECU.

The backup boost converter helps maintain battery voltage to prevent various functions from failing if power source voltage supplied from the backup boost converter drops due to the high electrical load when the engine is restarted by stop and start control.

The backup boost converter helps maintain the power source voltage if the battery voltage drops due to the high electrical load when the engine is restarted by stop and start control.

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
  • Headup display system
  • Air conditioning system
  • Intuitive parking assist system
  • Digital rear-view mirror system

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

Note

P323A19

Backup Boost Converter "A" Circuit Current Above Threshold

The following condition continues for 1 second or more (1 trip detection logic):

  • Overcurrent is detected at the B41, B42, B43, IG41 and EMOP terminals in the engine stop and start ECU
  • Wire harness or connector
  • Millimeter wave radar sensor assembly
  • Radio and display receiver assembly (w/ Display Audio System)
  • Blind spot monitor sensor LH (w/ Blind Spot Monitor System)
  • Blind spot monitor sensor RH (w/ Blind Spot Monitor System)
  • Clearance Warning ECU Assembly
  • Air conditioning control assembly
  • Oil pump with solenoid assembly
  • Inner rear view mirror assembly
  • Engine stop and start ECU

Blinks

DTC stored

SAE Code: P323A

CONFIRMATION DRIVING PATTERN

CONFIRMATION AFTER TROUBLESHOOTING

HINT:

  • If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.

    In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item "Status of Battery Charge Control" changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)

  • If the Techstream is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.

    If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.

  • After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
  • Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs.

Powertrain > Stop and Start > Clear DTCs

(e) Start the engine and warm it up.

(f) Drive the vehicle at 7 km/h (4 mph) or more.

CAUTION:

When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

(g) Depress the brake pedal and stop the vehicle.

(h) Keep the engine stopped by stop and start control for 1 second or more. (Keep the shift lever in D.)

(i) Release the brake pedal with the shift lever in D to start the engine.

HINT:

If the engine cranks slowly when the engine is restarted, it can be determined that the battery voltage is low.

(j) Check that DTCs are not output.

Powertrain > Stop and Start > Trouble Codes

STOP AND START SYSTEM OPERATION CHECK

HINT:

  • If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.

    In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item "Status of Battery Charge Control" changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)

  • If the Techstream is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.

    If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.

  • After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.

(a) Start the engine and warm it up.

(b) Turn the air conditioning system off.

(c) Drive the vehicle at 7 km/h (4 mph) or more.

CAUTION:

When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

(d) Depress the brake pedal and stop the vehicle.

(e) Allow the engine to stop by stop and start control. (Keep the shift lever in D.)

(f) Release the brake pedal with the shift lever in D to start the engine.

WIRING DIAGRAM

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 2023 MY RAV4 [10/2022 - 10/2023]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • 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 2023 MY RAV4 [10/2022 - 10/2023]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • 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 2023 MY RAV4 [10/2022 - 10/2023]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.

    Click here 2023 MY RAV4 [10/2022 - 10/2023]; STOP AND START: STOP AND START SYSTEM: REGISTRATION

  • Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

  • If electrical load from additional devices installed to the vehicle (aftermarket audio system, etc.) is applied to the B41, B42, B43 or IG41 terminal in the engine stop and start ECU, the fuse function of the backup boost converter may operate.

    If the fuse function of the backup boost converter operates, any systems connected to the B41, B42, B43 or IG41 terminal in the engine stop and start ECU will not operate.

  • If DTCs P279612 (Electromagnetic Oil Pump Circuit Short to Battery), P279614 (Electromagnetic Oil Pump Circuit Open), P279796 (Electromagnetic Oil Pump Component Internal Failure) and P323A19 (Backup Boost Converter "A" Circuit Current Above Threshold) are output simultaneously, troubleshoot for DTC P279612, P279614 or P279796 first, as a malfunction which causes DTC P279612, P279614 or P279796 to be stored may also cause DTC P323A19 to be stored.

    Click here 2023 MY RAV4 [10/2022 - 10/2023]; STOP AND START: STOP AND START SYSTEM: DIAGNOSTIC TROUBLE CODE CHART

  • DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.

    Click here 2019 - 2023 MY RAV4 [11/2018 - 10/2023]; STOP AND START: STOP AND START SYSTEM: DTC CHECK / CLEAR

  • Using the Techstream, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.

    Click here 2022 - 2023 MY RAV4 [12/2021 - 10/2023]; STOP AND START: STOP AND START SYSTEM: FREEZE FRAME DATA

PROCEDURE

1.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P323A19)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Stop and Start / Trouble Codes.

(e) Read the DTCs.

Powertrain > Stop and Start > Trouble Codes

Result

Proceed to

DTC P323A19 is output

A

DTC P279612, P279614 or P279796 and P323A19 are output

B

HINT:

If DTCs P323A19 and P279612, P279614 or P279796 are output simultaneously, troubleshoot for DTC P279612, P279614 or P279796 first.

B

GO TO DTC P279612, P279614 OR P279796

A

2.

CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BBC NO. 1 FUSE AND BBC NO. 2 FUSE)

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

(b) Remove the BBC NO. 1 fuse and BBC NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A33-1 (BIN2) - BBC NO. 2 fuse terminal 2

Always

Below 1 Ω

A33-3 (BIN1) - BBC NO. 1 fuse terminal 2

Always

Below 1 Ω

A33-1 (BIN2) or BBC NO. 2 fuse terminal 2 - Body ground and other terminals

Always

10 kΩ or higher

A33-3 (BIN1) or BBC NO. 1 fuse terminal 2 - Body ground and other terminals

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

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

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

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

(c) Disconnect the electrical key and tire pressure monitoring system receiver assembly connector. (w/ Tire Pressure Warning System)

(d) Disconnect the central gateway ECU (network gateway ECU) connector.

(e) Disconnect the millimeter wave radar sensor assembly connector. (w/ Dynamic Radar Cruise Control System)

(f) Disconnect the blind spot monitor sensor LH connector.

(g) Disconnect the blind spot monitor sensor RH connector.

(h) Disconnect the air conditioning control assembly connector.

(i) Disconnect the clearance warning ECU assembly connector.

(j) Disconnect the inner rear view mirror assembly connector. (w/ Digital Rear-view Mirror System)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A32-11 (B43) - P1-6 (+B)*1

Always

Below 1 Ω

A32-12 (B42) - G3-4 (+B1)*2

Always

Below 1 Ω

A32-2 (B41) - M8-7 (+B)*3

Always

Below 1 Ω

A32-3 (IG41) - M8-1 (IG)*3

Always

Below 1 Ω

A32-3 (IG41) - G72-11 (IG1)

Always

Below 1 Ω

A32-3 (IG41) - B9-8 (IGB)*4

Always

Below 1 Ω

A32-3 (IG41) - Q1-5 (BLB)

Always

Below 1 Ω

A32-3 (IG41) - Q13-5 (BRB)

Always

Below 1 Ω

A32-3 (IG41) - G24-9 (IG+)

Always

Below 1 Ω

A32-3 (IG41) - G25-1 (IG)*5

Always

Below 1 Ω

A32-3 (IG41) - H4-1 (IG)*6

Always

Below 1 Ω

A32-11 (B43) or P1-6 (+B)*1 - Body ground and other terminals

Always

10 kΩ or higher

A32-12 (B42) or G3-4 (+B1)*2 - Body ground and other terminals

Always

10 kΩ or higher

A32-2 (B41) or M8-7 (+B)*3 - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or M8-1 (IG)*3 - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or G72-11 (IG1) - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or B9-8 (IGB)*4 - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or Q1-5 (BLB) - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or Q13-5 (BRB) - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or G24-9 (IG+) - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or G25-1 (IG)*5 - Body ground and other terminals

Always

10 kΩ or higher

A32-3 (IG41) or H4-1 (IG)*6 - Body ground and other terminals

Always

10 kΩ or higher

  • *1: w/ Digital Rear-view Mirror System
  • *2: w/ Display Audio System
  • *3: w/ Tire Pressure Warning System
  • *4: w/ Dynamic Radar Cruise Control System
  • *5: except TMC Made
  • *6: for TMC Made
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK ENGINE STOP AND START ECU

*a

Component without harness connected

(Engine Stop and Start ECU)

-

-

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A32-2 (B41) - A34-6 (DGND)

Always

10 kΩ or higher

A32-3 (IG41) - A34-6 (DGND)

Always

10 kΩ or higher

A32-11 (B43) - A34-6 (DGND)

Always

10 kΩ or higher

A32-12 (B42) - A34-6 (DGND)

Always

10 kΩ or higher

NG

REPLACE ENGINE STOP AND START ECU

OK

5.

CHECK VEHICLE CONDITION (B41, B42, B43 OR IG41 CIRCUIT)

(a) Check that additional devices installed to the vehicle (aftermarket audio system, etc.) are not connected to the B41, B42, B43 or IG41 terminal circuit of the engine stop and start ECU.

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

A

TROUBLESHOOT ECUS CONNECTED TO TERMINALS B41, B42, B43 AND IG41

B

END (REMOVE ADDITIONAL DEVICE)