STOP AND START SYSTEM, Diagnostic DTC:P323B

DTC Code DTC Name
P323B Backup Boost Converter

DESCRIPTION

Refer to DTC B22C0

Click here

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

Any of the following conditions is 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

  • B41 and B42 terminal voltage is 6.0 V or less and BBC is not overheating

  • IG11, IG31 and IG41 terminals voltage is 6.0 V or less

  • Engine stop and start ECU

  • Wire harness or connector

  • Battery

  • BBC NO. 1 fuse

  • BBC NO. 2 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.

Click here


  1. Tech Tips


    • 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 temperature at 11°C (51°F) or higher, the refresh charge will be completed.)

    • If the GTS 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.

    CONFIRMATION AFTER TROUBLESHOOTING


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON 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. Stop the vehicle, move the shift lever to neutral and release the clutch pedal.

    7. Keep the engine stopped by stop and start control for 1 second or more.

    8. Depress the clutch pedal and 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 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 temperature at 11°C (51°F) or higher, the refresh charge will be completed.)

    • If the GTS 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.


    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 the confirmation driving pattern, obey all speed limits and traffic laws.

    4. Stop the vehicle, move the shift lever to neutral and release the clutch pedal.

    5. Allow the engine to stop by stop and start control.

    6. Depress the clutch pedal and start the engine.

WIRING DIAGRAM


CAUTION / NOTICE / HINT

Note


  • 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 sensor 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.

Click here

PROCEDURE


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


    1. Disconnect the A61 engine stop and start ECU connector.

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

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-1 (BIN2) - BBC NO. 2 fuse terminal 2 Always Below 1 Ω
      A61-3 (BIN1) - BBC NO. 1 fuse terminal 2 Always Below 1 Ω
      A61-1 (BIN2) - Body ground and other terminals Always 10 kΩ or higher
      BBC NO. 2 fuse terminal 2 - Body ground and other terminals Always 10 kΩ or higher
      A61-3 (BIN1) - Body ground and other terminals Always 10 kΩ or higher
      BBC NO. 1 fuse terminal 2 - Body ground and other terminals 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. A001XEIC35
      *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
      A61-1 (BIN2) - Body ground Always 9.5 to 14 V
      A61-3 (BIN1) - Body ground Always 9.5 to 14 V

    3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F77-21 (IG1) - Body ground Ignition switch ON 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 A61 and A62 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
      A61-2 (GND2) - Body ground Always Below 1 Ω
      A61-8 (GND1) - Body ground Always Below 1 Ω
      A62-6 (DGND) - 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 F77 engine stop and start ECU connector.

    2. Disconnect the 3A instrument panel junction block assembly (main body ECU (multiplex network body ECU)) connector.

    3. Disconnect the F54 pre-collision city buzzer connector.

    4. Disconnect the F38 clearance warning ECU assembly connector (w/ Simple Intelligent Parking Assist System).

    5. Disconnect the R5 forward recognition camera connector.

    6. Disconnect the R8 forward recognition hood connector.

    7. Disconnect the F61 air conditioning control assembly connector.

    8. Disconnect the A2 millimeter wave radar sensor assembly connector.

    9. Disconnect the M62 blind spot monitor sensor LH connector.

    10. Disconnect the M63 blind spot monitor sensor RH connector.

    11. Disconnect the R7 inner rear view mirror assembly connector.

    12. Disconnect the F74 network gate ECU connector.

    13. Disconnect the M23 door control and tire pressure monitoring system receiver assembly connector.

    14. Disconnect the F48 radio and display receiver assembly connector.

    15. Disconnect the F23 power steering ECU assembly connector.

    16. Disconnect the A42 skid control ECU (brake actuator assembly) connector.

    17. Disconnect the F69 spiral cable with sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F77-3 (IG41) - 3A-15 Always Below 1 Ω
      F77-3 (IG41) - F54-2 (IG1) Always Below 1 Ω
      F77-3 (IG41) - F38-8 (IG)*1 Always Below 1 Ω
      F77-3 (IG41) - R5-7 (IGB) Always Below 1 Ω
      F77-3 (IG41) - R8-1 (IG1) Always Below 1 Ω
      F77-3 (IG41) - F61-10 (IG+) Always Below 1 Ω
      F77-3 (IG41) - A2-8 (IGB) Always Below 1 Ω
      F77-3 (IG41) - A62-5 (BLB) Always Below 1 Ω
      F77-3 (IG41) - A63-5 (BRB) Always Below 1 Ω
      F77-3 (IG41) - R7-4 (IG) Always Below 1 Ω
      F77-3 (IG41) - F74-11 (IG1) Always Below 1 Ω
      F77-3 (IG41) - M23-1 (IG) Always Below 1 Ω
      F77-2 (B41) - M23-7 (+B) Always Below 1 Ω
      F77-12 (B42) - F48-4 (+B1) Always Below 1 Ω
      F77-6 (IG11) - F23-1 (IG) Always Below 1 Ω
      F77-1 (IG31) - A42-36 (IG1) Always Below 1 Ω
      F77-1 (IG31) - F69-4 (IG1) Always Below 1 Ω
      F77-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
      F77-2 (B41) - Body ground and other terminals Always 10 kΩ or higher
      F77-12 (B42) - Body ground and other terminals Always 10 kΩ or higher
      F77-6 (IG11) - Body ground and other terminals Always 10 kΩ or higher
      F77-1 (IG31) - Body ground and other terminals Always 10 kΩ or higher

      • *1: w/ Simple Intelligent Parking Assist System

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR