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 to the audio and visual system, etc. 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.

The backup boost converter helps maintain the power source voltage at 13.5 V when its mode changes from standby mode to compensation mode. If the backup boost converter cannot maintain the voltage at the specified level when the engine is restarted by stop and start control, the engine stop and start ECU stores a DTC and blinks the stop and start cancel indicator light. The stop and start cancel indicator light will remain blinking during the trip in which the malfunction occurred.

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*1 when the ignition 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 ignition switch is turned to ON.


  • *1: A semiconductor fuse self-resets according to electric signals.


    The backup boost converter supplies power to:

  • Main body ECU (multiplex network body ECU)

  • Skid control ECU (brake actuator assembly)

  • Spiral with sensor cable sub-assembly

  • Yaw rate sensor

  • Power steering ECU assembly

  • Electric parking brake ECU (parking brake with bracket actuator assembly)

  • Air conditioning control assembly

  • Radio receiver assembly or radio and display receiver assembly

  • Tire pressure warning ECU and receiver

  • Inner rear view mirror assembly

  • Combination meter assembly

DTC No. DTC Detection Condition Trouble Area
B22C0

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


  • Overcurrent is detected at the BO1 and IGO1 terminals in the engine stop and start ECU

  • Engine stop and start ECU

  • Wire harness or connector

  • Spiral with sensor cable sub-assembly

  • Yaw rate sensor

  • Skid control ECU (brake actuator assembly)

  • Power steering ECU assembly

  • Radio receiver assembly (for Radio Receiver Type)

  • Radio and display receiver assembly (for Radio and Display Receiver Type)

  • Inner rear view mirror assembly (w/ Automatic Glare-resistant EC Mirror)

  • Electric parking brake ECU (parking brake with bracket actuator assembly)

  • Main body ECU (Multiplex network body ECU)

  • Air conditioning control assembly

  • Tire pressure warning ECU and receiver (w/ Tire Pressure Warning System)

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

A004T9CE02
A004T0VE01
A004RP4E01
A004Q9XE01

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, perform deceleration sensor zero point clear and calibration 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.

  • If electrical load from additional devices installed on the vehicle (aftermarket audio system, etc.) is applied to the BO1 or IGO1 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 BO1 or IGO1 terminal in the engine stop and start ECU will not operate.

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 - 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


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ENGINE STOP AND START ECU


    1. Disconnect the engine stop and start ECU connector.

      A004PZIE02
      Text in Illustration
      *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
      D139-2 (BO1) - A79-8 (GND) Always 10 kΩ or higher
      D139-12 (IGO1) - A79-8 (GND) Always 10 kΩ or higher

    NG

    REPLACE ENGINE STOP AND START ECU Click here

    OK

  4. CHECK VEHICLE CONDITION (BO1, IGO1 CIRCUIT)


    1. Check that additional devices installed to the vehicle (aftermarket audio system, etc.) are not connected to the BO1 or IGO1 terminal circuit in 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

    GO TO TROUBLE AREAS (TROUBLESHOOTING PROCEDURE FOR ECUS CONNECTED TO BO1 AND IGO1 TERMINALS)

    B

    END (REMOVE ELECTRICAL LOAD FROM ADDITIONAL DEVICE)