STOP AND START SYSTEM, Diagnostic DTC:P323B

DTC Code DTC Name
P323B Backup Boost Converter

DESCRIPTION

Refer to DTC B22C0

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DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Memory
P323B Backup Boost Converter

Any of the following conditions are met for 1 second or more (1 trip detection logic):


  • BBC malfunction is detected

  • Engine stop and start ECU thermistor temperature is 128°C (262.4°F) or higher

  • Difference in temperature between thermistor 1 and thermistor 2 of the engine stop and start ECU is 40°C (104°F) or higher

  • BO1 voltage is 6.0 V or less and BBC is not overheating

  • IGO1 voltage is 6.0 V or less

  • Engine stop and start ECU

  • Wire harness or connector

  • Battery

  • BBC NO. 1 fuse

 Blinks DTC stored

CONFIRMATION DRIVING PATTERN

Tech Tips

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.

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  1. Tech Tips


    • If the cable is disconnected from the negative (-) battery terminal, stop and start control is prohibited until refresh charge is completed. In this case, drive the vehicle approximately 5 to 40 minutes until refresh charge is completed and stop and start control operation is permitted.

    • 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.

    CONFIRMATION AFTER TROUBLESHOOTING


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

    3. Clear the DTCs.

      Click here


      Powertrain > Stop and Start > Clear DTCs

    4. Start the engine and warm it up.

    5. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

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

    6. Depress the brake pedal and stop the vehicle.

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

    8. Release the brake pedal with the shift lever in D to start the engine.

      Tech Tips

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

    9. Check that DTCs are not output.

      Click here


      Powertrain > Stop and Start > Trouble Codes

  2. STOP AND START SYSTEM OPERATION CHECK

    Tech Tips

    If the cable is disconnected from the negative (-) battery terminal, stop and start control is prohibited until refresh charge is completed. In this case, drive the vehicle approximately 5 to 40 minutes until refresh charge is completed and stop and start control operation is permitted.


    1. Start the engine and warm it up.

    2. Turn the air conditioning system off.

    3. Drive the vehicle at 7 km/h (4.3 mph) or more.

      CAUTION:

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

    4. Depress the brake pedal and stop the vehicle.

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

    6. Release the brake pedal with the shift lever in D to start the engine.

WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note


  • for 8AR-FTS:

    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.

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  • for 3ZR-FAE:

    When replacing the engine stop and start ECU with a new one, make sure to download the previous status (number of starter operations) of the old engine stop and start ECU. After replacing the engine stop and start ECU, turn the engine switch on (IG) and wait 20 seconds, then confirm that "OK" is displayed for the Data List item "Oper Prohibition (O/P Air Bleeding)". Then upload the previous status (number of starter operations) to the 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

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

Tech Tips

Using the GTS, 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.

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PROCEDURE


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


    1. Disconnect the A37 engine stop and start ECU connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A37-7 (BIN) - BBC NO. 1 fuse terminal 2 Always Below 1 Ω
      A37-7 (BIN) - 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU POWER SOURCE CIRCUIT)


    1. B008HKJC27
      *a

      Front view of wire harness connector

      (to Engine Stop and Start ECU)

      Disconnect the engine stop and start ECU connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A37-7 (BIN) - Body ground Always 9.5 to 14 V

    3. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I57-17 (IG1) - Body ground Engine switch on (IG) 9.5 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BODY GROUND)


    1. Disconnect the A37 engine stop and start ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A37-8 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the I57 engine stop and start ECU connector.

    2. Disconnect the A36 skid control ECU (brake actuator assembly) connector.

    3. Disconnect the n2 power steering ECU assembly connector. (w/ Power Tilt and Power Telescopic)

    4. Disconnect the n3 power steering ECU assembly connector. (w/o Power Tilt and Power Telescopic)

    5. Disconnect the I6 spiral with sensor cable sub-assembly connector.

    6. Disconnect the I19 driving support ECU assembly connector. (w/ Dynamic Radar Cruise Control System)

    7. Disconnect the T5 inner rear view mirror connector. (w/ EC Mirror)

    8. Disconnect the A21 millimeter wave radar sensor assembly connector. (w/ Dynamic Radar Cruise Control System)

    9. Disconnect the T10 Lane departure warning camera connector. (w/ Lane Departure Alert System)

    10. Disconnect the I67 network gateway ECU connector.

    11. Disconnect the I13 air conditioning control assembly connector.

    12. Disconnect the P19 parking assist ECU connector. (w/ Panoramic View Monitor System)

    13. Disconnect the Q46 tire pressure warning ECU and receiver connector. (Tire Pressure Warning ECU and Receiver (for LH Side))

    14. Disconnect the P11 tire pressure warning ECU and receiver (door control and tire pressure monitoring system receiver assembly) connector. (Tire Pressure Warning ECU and Receiver (for RH Side))

    15. Disconnect the X1 blind spot monitor sensor RH connector. (w/ Blind Spot Monitor System)

    16. Disconnect the V1 blind spot monitor sensor LH connector. (w/ Blind Spot Monitor System)

    17. Disconnect the I40 telematics transceiver connector. (w/ Telematics Transceiver)

    18. Disconnect the J5 combination meter mirror ECU connector. (w/ Headup Display)

    19. Disconnect the I71 remote operation controller assembly connector. (w/ Navigation System)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I57-2 (BO1) - P19-2 (+B)*1 Always Below 1 Ω
      I57-2 (BO1) - I40-1 (+B)*11 Always Below 1 Ω
      I57-2 (BO1) - I71-1 (+B)*8 Always Below 1 Ω
      I57-12 (IGO1) - A36-12 (IG1) Always Below 1 Ω
      I57-12 (IGO1) - n2-1 (IG)*9 Always Below 1 Ω
      I57-12 (IGO1) - n3-1 (IG)*10 Always Below 1 Ω
      I57-12 (IGO1) - I19-30 (B)*2 Always Below 1 Ω
      I57-12 (IGO1) - I6-4 (IG1) Always Below 1 Ω
      I57-12 (IGO1) - T5-1 (IG)*3 Always Below 1 Ω
      I57-12 (IGO1) - T10-7 (IGB)*4 Always Below 1 Ω
      I57-12 (IGO1) - A21-5 (IGB)*2 Always Below 1 Ω
      I57-12 (IGO1) - I67-10 (IG1) Always Below 1 Ω
      I57-12 (IGO1) - I13-8 (IG+) Always Below 1 Ω
      I57-12 (IGO1) - Q46-1 (IG)*5 Always Below 1 Ω
      I57-12 (IGO1) - P11-1 (IG)*6 Always Below 1 Ω
      I57-12 (IGO1) - X1-5 (BRB)*7 Always Below 1 Ω
      I57-12 (IGO1) - V1-5 (BLB)*7 Always Below 1 Ω
      I57-12 (IGO1) - I40-7 (IG2)*11 Always Below 1 Ω
      I57-12 (IGO1) - J5-1 (IG)*12 Always Below 1 Ω
      I57-12 (IGO1) - P19-6 (IG)*1 Always Below 1 Ω
      I57-2 (BO1) - Body ground Always 10 kΩ or higher
      I57-12 (IGO1) - Body ground Always 10 kΩ or higher

      • *1: w/ Panoramic View Monitor System

      • *2: w/ Dynamic Radar Cruise Control System

      • *3: w/ EC Mirror

      • *4: w/ Lane Departure Alert System

      • *5: Tire Pressure Warning ECU and Receiver (for LH Side)

      • *6: Tire Pressure Warning ECU and Receiver (for RH Side)

      • *7: w/ Blind Spot Monitor System

      • *8: w/ Navigation System

      • *9: w/ Power Tilt and Power Telescopic

      • *10: w/o Power Tilt and Power Telescopic

      • *11: w/ Telematics Transceiver

      • *12: w/ Headup Display

      Result
      Proceed to
      OK
      NG

      Tech Tips

      The installation location of the tire pressure warning ECU and receiver differs depending on the specification. Refer to the following link for the installation location information.

      Click here


    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR