STOP AND START SYSTEM, Diagnostic DTC:B22C0

DTC Code DTC Name
B22C0 BBC Overcurrent

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.

Tech Tips

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 engine 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 engine switch is turned on (IG).

*: A semiconductor fuse self resets according to electric signal.


    The backup boost converter supplies power to:

  • Tire pressure warning system

  • Power steering system

  • Lighting system

  • Telematics system

  • Navigation system

  • Audio and visual system

  • Blind spot monitor system

  • Headup display system

  • Lexus safety system +

  • CAN communication system

  • Lexus parking assist-sensor system

  • Panoramic view monitor system

  • Vehicle stability control system

  • Meter / gauge system

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Memory
B22C0 BBC Overcurrent

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


  • Overcurrent is detected at the B41, B42, B43 and IG41 terminals in the engine stop and start ECU

  • Engine stop and start ECU

  • Wire harness or connector

  • Tire pressure warning ECU and receiver*1

  • Front door trim board sub-assembly RH (front door ambient illumination light RH)*2

  • Front door trim board sub-assembly LH (front door ambient illumination light LH)*2

  • Rear door trim board sub-assembly RH (rear door ambient illumination light RH)*2

  • Rear door trim board sub-assembly RH (rear door ambient illumination light RH)*2

  • No. 1 interior illumination light assembly RH (footwell light RH)

  • No. 1 interior illumination light assembly LH (footwell light LH)

  • No. 1 interior illumination light assembly (front console light)

  • Interior illumination light sub-assembly (instrument panel ambient illumination light)*3

  • DOME CUT NO. 2 relay

  • Spot light assembly

  • Radio receiver assembly

  • Multi-display assembly*6

  • Accessary meter assembly*7

  • Remote touch (remote operation board)*4

  • LEXUS display audio controller (remote operation board)*5

  • Blind spot monitor sensor LH*8

  • Blind spot monitor sensor RH*8

  • Millimeter wave radar sensor assembly*9

  • Driving support ECU assembly*9

  • Network gateway ECU

  • Lane departure warning camera*9

  • Clearance warning ECU assembly*10

  • Meter mirror sub-assembly*11

 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. 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 it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.


    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 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 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

B005PIRE01
B005P4UE04
B005OZZE03
B005LTQE02
B005ON7E01
B005PPIE02
B005N4BE06

CAUTION / NOTICE / HINT

Note


  • Before replacing the engine stop and start ECU, read the number of starter operations and total number of engine starts 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, airbag sensor assembly*1 or yaw rate and acceleration sensor*2, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.

    Click here


    • *1: for Optitron Meter Type

    • *2: for TFT Meter Type

  • 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

  • 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 P1539 and B22C0 are output simultaneously, troubleshoot for DTC P1539 (oilpump malfunction) first, as a malfunction which causes DTC P1539 to be stored mayalso cause DTC B22C0 (BBC boost converter over-current) to be stored.

PROCEDURE


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


    1. Disconnect the A65 engine stop and start ECU connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A65-1 (BIN2) - BBC NO. 2 fuse terminal 2 Always Below 1 Ω
      A65-3 (BIN1) - BBC NO. 1 fuse terminal 2 Always Below 1 Ω
      A65-1 (BIN2) - Body ground Always 10 kΩ or higher
      BBC NO. 2 fuse terminal 2 - Body ground Always 10 kΩ or higher
      A65-3 (BIN1) - 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 - EACH ECU OR SENSOR)


    1. Disconnect the J46 engine stop and start ECU connector.

    2. Disconnect the S54 tire pressure warning ECU and receiver connector.*1

    3. Disconnect the R23 tire pressure warning ECU and receiver connector.*2

    4. Disconnect the N12 front door trim board sub-assembly LH (front door ambient illumination light LH) connector.*3

    5. Disconnect the M12 front door trim board sub-assembly RH (front door ambient illumination light RH) connector.*3

    6. Disconnect the Q6 rear door trim board sub-assembly LH (rear door ambient illumination light LH) connector.*3

    7. Disconnect the Q5 rear door trim board sub-assembly RH (rear door ambient illumination light RH) connector.*3

    8. Disconnect the J13 No. 1 interior illumination light assembly LH (footwell light LH) connector.

    9. Disconnect the J37 No. 1 interior illumination light assembly RH (footwell light RH) connector.

    10. Disconnect the J18 No. 1 interior illumination light assembly (front console light) connector.

    11. Disconnect the K10 interior illumination light sub-assembly (instrument panel ambient illumination light) connector.*4

    12. Disconnect the J50 radio receiver assembly connector.*5

    13. Disconnect the J52 radio receiver assembly connector.*6

    14. Disconnect the J56 multi-display assembly connector.*7

    15. Disconnect the J137 accessory meter assembly connector.*8

    16. Disconnect the g1 remote touch (remote operation board) connector.*5

    17. Disconnect the J59 Lexus display audio controller (remote operation board) connector.*6

    18. Disconnect the X2 blind spot monitor sensor LH connector.*9

    19. Disconnect the W2 blind spot monitor sensor RH connector.*9

    20. Disconnect the A70 millimeter wave radar sensor assembly connector.*10

    21. Disconnect the A72 driving support ECU assembly connector.*10

    22. Disconnect the J75 Network gateway ECU connector.

    23. Disconnect the U14 forward recognition camera*1 connector.*10

    24. Disconnect the J73 parking assist ECU connector.*11

    25. Disconnect the J38 clearance warning ECU assembly connector.*12

    26. Disconnect the K1 meter mirror sub-assembly connector.*13

    27. Disconnect the 2C instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J46-2 (B41) - R23-7 (+B)*2 Always Below 1 Ω
      J46-2 (B41) - g1-1 (+B)*8 Always Below 1 Ω
      J46-2 (B41) - J73-2 (+B)*11 Always Below 1 Ω
      J46-2 (B41) - K1-1 (+B)*13 Always Below 1 Ω
      J46-2 (B41) - 2C-7 Always Below 1 Ω
      J46-12 (B42) - J50-17 (+B1)*5 Always Below 1 Ω
      J46-12 (B42) - J52-4 (+B1)*6 Always Below 1 Ω
      J46-11 (B43) - J56-12 (B)*7 Always Below 1 Ω
      J46-11 (B43) - J137-12 (B)*8 Always Below 1 Ω
      J46-11 (B43) - N12-1 (+)*3 Always Below 1 Ω
      J46-11 (B43) - M12-1 (+)*3 Always Below 1 Ω
      J46-11 (B43) - Q6-1 (+)*3 Always Below 1 Ω
      J46-11 (B43) - Q5-1 (+)*3 Always Below 1 Ω
      J46-11 (B43) - J13-2 (B) Always Below 1 Ω
      J46-11 (B43) - J37-2 (B) Always Below 1 Ω
      J46-11 (B43) - J18-2 (B) Always Below 1 Ω
      J46-11 (B43) - K10-2 (RRIL)*4 Always Below 1 Ω
      J46-3 (IG41) - S54-1 (IG)*1 Always Below 1 Ω
      J46-3 (IG41) - R23-1 (IG)*2 Always Below 1 Ω
      J46-3 (IG41) - X2-5 (BLB)*9 Always Below 1 Ω
      J46-3 (IG41) - W2-5 (BRB)*9 Always Below 1 Ω
      J46-3 (IG41) - A70-8 (IGB)*10 Always Below 1 Ω
      J46-3 (IG41) - A72-7 (B)*10 Always Below 1 Ω
      J46-3 (IG41) - J75-11 (IG1) Always Below 1 Ω
      J46-3 (IG41) - U14-7 (IGB)*10 Always Below 1 Ω
      J46-3 (IG41) - J73-6 (IG)*11 Always Below 1 Ω
      J46-3 (IG41) - J38-1 (IG)*12 Always Below 1 Ω
      J46-3 (IG41) - K1-2 (IG)*13 Always Below 1 Ω
      J46-2 (B41) - Body ground Always 10 kΩ or higher
      J46-12 (B42) - Body ground Always 10 kΩ or higher
      J46-11 (B43) - Body ground Always 10 kΩ or higher
      J46-3 (IG41) - Body ground Always 10 kΩ or higher
      2C-7 - Body ground Always 10 kΩ or higher

      • *1: for Tire Pressure Warning ECU and Receiver (Stand Alone)

      • *2: for Tire Pressure Warning ECU and Receiver Integrated with Electrical Key Receiver

      • *3: w/ Door Ambient Illumination Light

      • *4: w/ Instrument Panel Ambient Illumination Light

      • *5: w/ Navigation System or Audio and Visual System (for 12.3 Inch Display)

      • *6: w/ Audio and Visual System (for 8 Inch Display)

      • *7: for 8 Inch Display

      • *8: for 12.3 Inch Display

      • *9: w/ Blind Spot Monitor System

      • *10: w/ Lexus Safety System +

      • *11: w/ Panoramic View Monitor System

      • *12: w/ Lexus Parking Assist-sensor System

      • *13: w/ Headup Display System

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (DOME CUT NO. 2 RELAY)


    1. Remove the instrument panel junction block assembly.

      Click here

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

      B005PPOC09
      *1 Main Body ECU (Multiplex Network Body ECU) - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      2B-5 - 2C-7

      Battery positive (+) → 2A-16

      Battery negative (-) → 2A-19

      		 Below 1 Ω
      Battery not connected to 2A-16 and 2A-19 10 kΩ or higher
      2A-16 or 2A-19 - 2C-7 Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (DOME CUT NO. 2 RELAY) - SPOT LIGHT ASSEMBLY)


    1. Disconnect the 2B instrument panel junction block assembly connector.

    2. Disconnect the U13 spot light assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2B-5 - U13-2 (B) Always Below 1 Ω
      2B-5 - Body ground Always 10 kΩ or higher
      U13-2 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK ENGINE STOP AND START ECU


    1. Disconnect the A65, A66 and J46 engine stop and start ECU connectors.

      B005OMZC22
      *a

      Component without harness connected

      (Engine Stop and Start ECU)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J46-3 (IG41) - A66-6 (DGND) Always 10 kΩ or higher
      J46-2 (B41) - A66-6 (DGND) Always 10 kΩ or higher
      J46-11 (B43) - A66-6 (DGND) Always 10 kΩ or higher
      J46-12 (B42) - A66-6 (DGND) Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ENGINE STOP AND START ECU Click here

    OK

  6. CHECK VEHICLE CONDITION (B41, B42, B43, IG41 CIRCUIT)


    1. 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
      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)