STOP AND START SYSTEM(for 2WW), 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 is met for 1 second or more (1 trip detection logic):


  • Backup boost converter 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 voltage is 6.0 V or less, backup boost converter is not overheating and backup boost converter output overcurrent is not detected

  • IG41 voltage is 6.0 V or less and backup boost converter output overcurrent is not detected

  • Engine stop and start ECU

  • Wire harness or connector

  • Battery

  • BBC 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.

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  1. CONFIRMATION AFTER TROUBLESHOOTING

    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 60 minutes until refresh charge is completed and stop and start control operation is permitted.

    • Allow the engine to idle for 3 minutes after the engine warms up and check that the engine speed is within 50 rpm of the target idle speed.


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

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      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 the 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 battery voltage is low.

    9. Check that DTCs are not output.

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      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 60 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 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

Refer to DTC B22C0

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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.

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  • 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.

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  • 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.

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  • 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, BBC NO. 2 FUSES)


    1. Disconnect the A86 engine stop and start ECU connector.

    2. Remove the BBC fuse from the engine room relay block and junction block assembly.

    3. Remove the BBC NO. 2 fuse from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A86-1 (BIN2) - BBC NO. 2 fuse terminal 2 Always Below 1 Ω
      A86-3 (BIN1) - BBC fuse terminal 2 Always Below 1 Ω
      A86-1 (BIN2) - Body ground Always 10 kΩ or higher
      BBC NO. 2 fuse terminal 2 - Body ground Always 10 kΩ or higher
      A86-3 (BIN1) - Body ground Always 10 kΩ or higher
      BBC 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. A01QT9HC05
      *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
      A86-1 (BIN2) - Body ground Always 9.5 to 14 V
      A86-3 (BIN1) - 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 Switch Condition Specified Condition
      G87-21 (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 A66 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
      A66-6 (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 G87 engine stop and start ECU connector.

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

    3. w/ EC Mirror:

      Disconnect the Q14*1 or Q15*2 inner rear view mirror assembly connector.


      • *1: w/o Lane Departure Alert System

      • *2: w/ Lane Departure Alert System

    4. w/ Tire Pressure Warning System:

      Disconnect the M30 tire pressure warning ECU and receiver connector.

    5. Disconnect the G170 network gateway ECU connector.

    6. w/ Dynamic Radar Cruise Control System:

      Disconnect the Z6 millimeter wave radar sensor assembly connector.

    7. w/ Dynamic Radar Cruise Control System:

      Disconnect the G168 driving support ECU assembly connector.

    8. w/ Lane Departure Alert System:

      Disconnect the Q17 lane departure warning camera connector.

    9. w/ Blind Spot Monitor System:

      Disconnect the R1 blind spot monitor sensor LH connector.

    10. w/ Blind Spot Monitor System:

      Disconnect the T1 blind spot monitor sensor RH connector.

    11. w/ Panoramic View Monitor System:

      Disconnect the a2 parking assist ECU connector.

    12. for Radio Receiver Type:

      Disconnect the G46 radio receiver assembly connector.

    13. for Navigation Receiver Type:

      Disconnect the G137 navigation receiver assembly connector.

    14. for Radio and Display Receiver Type:

      Disconnect the G141 radio and display receiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G87-3 (IG41) - 3D-40 (IG) Always Below 1 Ω
      G87-3 (IG41) - Q14-1 (IG)*1, *10 Always Below 1 Ω
      G87-3 (IG41) - Q15-4 (IG)*2, *10 Always Below 1 Ω
      G87-3 (IG41) - M30-1 (IG)*3 Always Below 1 Ω
      G87-3 (IG41) - G170-11 (IG1) Always Below 1 Ω
      G87-3 (IG41) - Z6-8 (IGB)*4 Always Below 1 Ω
      G87-3 (IG41) - G168-7 (IGB)*4 Always Below 1 Ω
      G87-3 (IG41) - Q17-7 (IGB)*2 Always Below 1 Ω
      G87-3 (IG41) - R1-5 (BLB)*5 Always Below 1 Ω
      G87-3 (IG41) - T1-5 (BRB)*5 Always Below 1 Ω
      G87-3 (IG41) - a2-6 (IG)*6 Always Below 1 Ω
      G87-2 (B41) - a2-2 (+B)*6 Always Below 1 Ω
      G87-2 (B41) - G46-4 (+B1)*7 Always Below 1 Ω
      G87-2 (B41) - G137-4 (+B1)*8 Always Below 1 Ω
      G87-2 (B41) - G141-4 (+B1)*9 Always Below 1 Ω
      G87-3 (IG41) - Body ground Always 10 kΩ or higher
      G87-2 (B41) - Body ground Always 10 kΩ or higher

      • *1: w/o Lane Departure Alert System

      • *2: w/ Lane Departure Alert System

      • *3: w/ Tire Pressure Warning System

      • *4: w/ Dynamic Radar Cruise Control System

      • *5: w/ Blind Spot Monitor System:

      • *6: w/ Panoramic View Monitor System

      • *7: for Radio Receiver Type

      • *8: for Navigation Receiver Type

      • *9: for Radio and Display Receiver Type

      • *10: w/ EC Mirror

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR