STOP AND START SYSTEM, Diagnostic DTC:P323B

DTC Code DTC Name
P323B Backup Boost Converter

DESCRIPTION

Refer to DTC B22C0 Click here.

DTC No. DTC Detection Condition Trouble Area
P323B

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

  • BO1 voltage is 6.0 V or less, backup boost converter is not overheating and backup boost converter output overcurrent is not detected

  • IGO1 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

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. 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 40 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 Click here.

    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 Click here.

  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 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 Click here.

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 yaw rate sensor, 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 FUSE)


    1. Disconnect the A79 engine stop and start ECU connector.

    2. Remove the BBC fuse from the 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
      A79-7 (BIN) - BBC fuse terminal 2 Always Below 1 Ω
      A79-7 (BIN) - Body ground Always 10 kΩ or higher
      BBC fuse terminal 2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A004RP5E02
      Text in Illustration
      *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
      A79-7 (BIN) - 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
      D139-17 (IG1) - Body ground Ignition switch ON 9.5 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the A79 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
      A79-8 (GND) - Body ground Always Below 1 Ω

    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 D139 engine stop and start ECU connector.

    2. for Radio Receiver Type:

      Disconnect the D1 and D129 radio receiver assembly connectors.

    3. for Radio and Display Receiver Type:

      Disconnect the D125 and D124 radio and display receiver assembly connectors.

    4. Disconnect the DH instrument panel junction block assembly (main body ECU (multiplex network body ECU)).

    5. Disconnect the A84 skid control ECU (brake actuator assembly) connector.

    6. Disconnect the D69 yaw rate sensor connector.

    7. Disconnect the D167 spiral with sensor cable sub-assembly connector.

    8. Disconnect the D50 power steering ECU assembly connector.

    9. w/ Automatic Glare-resistant EC mirror:

      Disconnect the K6 inner rear view mirror assembly connector.

    10. Disconnect the I1 electric parking brake ECU (parking brake with bracket actuator assembly) connector.

    11. Disconnect the D12 air conditioning control assembly connector.

    12. w/ Tire Pressure Warning System:

      Disconnect the G65*1 or L2*2 tire pressure warning ECU and receiver connector.


      • *1: for Sedan

      • *2: for Wagon

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D139-2 (BO1) - D1-4 (+B1)*1 Always Below 1 Ω
      D139-2 (BO1) - D125-4 (+B1)*2 Always Below 1 Ω
      D139-12 (IGO1) - D129-1 (IG)*1 Always Below 1 Ω
      D139-12 (IGO1) - D124-1 (IG)*2 Always Below 1 Ω
      D139-12 (IGO1) - A84-4 (IG1) Always Below 1 Ω
      D139-12 (IGO1) - D50-6 (IG) Always Below 1 Ω
      D139-12 (IGO1) - DH-13 (IG) Always Below 1 Ω
      D139-12 (IGO1) - D167-5 (IG) Always Below 1 Ω
      D139-12 (IGO1) - D69-1 (IGA) Always Below 1 Ω
      D139-12 (IGO1) - K6-4 (IG)*3 Always Below 1 Ω
      D139-12 (IGO1) - I1-19 (IG) Always Below 1 Ω
      D139-12 (IGO1) - D12-5 (IG+) Always Below 1 Ω
      D139-12 (IGO1) - G65-1 (IG)*4 Always Below 1 Ω
      D139-12 (IGO1) - L2-1 (IG)*5 Always Below 1 Ω
      D139-2 (BO1) - Body ground Always 10 kΩ or higher
      D139-12 (IGO1) - Body ground Always 10 kΩ or higher

      • *1: for Radio Receiver Type

      • *2: for Radio and Display Receiver Type

      • *3: w/ Automatic Glare-resistant EC Mirror

      • *4: w/ Tire Pressure Warning System, for Sedan

      • *5: w/ Tire Pressure Warning System, for Wagon


    OK

    REPLACE ENGINE STOP AND START ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR