HYBRID CONTROL SYSTEM Brake Override System

DESCRIPTION

When the vehicle is being driven, depressing the accelerator pedal and brake pedal will activate the brake override system to restrict driving torque. The conditions for activating the brake override system as well as the items that are controlled are explained below.

• Activation Conditions:
  

  • The accelerator pedal and brake pedal are depressed at the same time.

    Note

    Brake override control may not be performed depending on the relationship between accelerator opening and vehicle speed.

• Items Controlled:
  

  • Controls driving force

    Tech Tips

    
    

    • When the control is operating, requested accelerator torque is controlled in accordance with the brake pedal stroke.

    • When the driving force is reduced to a specified level because the accelerator pedal and brake pedal are depressed at the same time, an indicator is displayed on the meter. (Operation of the system can be confirmed when the indicator is displayed on the meter.)

• Deactivation Conditions:
  

  • The accelerator pedal or brake pedal is released.

CAUTION / NOTICE / HINT

• Inspection Method

  Drive at 10 km/h (6.25 mph), depress the accelerator pedal by 1/2 to 3/4 and keep it in that position. Under these conditions, if driving torque is controlled when the brake pedal is depressed by the left foot of the driver, it can be confirmed that the brake override system has operated.

  CAUTION:

  Perform this road test only in an appropriate safe location, in accordance with all local laws.

  Pay careful attention to the surroundings when performing the road test.

  Note

  When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work (If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).

  Tech Tips

  The brake override system restricts driving torque if the brake pedal is depressed when driving with the accelerator pedal depressed. If a customer reports experiencing a loss of power (driving torque) after the accelerator and brake pedals have both been intentionally depressed, explain that this is not a malfunction, and depressing both the accelerator and brake pedals at the same time should be avoided.

PROCEDURE

1. CHECK DTC OUTPUT (HEALTH CHECK)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Enter the following menus: System Select / Health Check.

   4. Check for DTCs.

      Result
      Result Proceed to No DTCs are output. A DTCs are output. B

   5. Turn the power switch off.

   
   

   B

   GO TO DTC CHART

   A

2. READ VALUE USING GTS (MASTER CYLINDER CONTROL TORQUE)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Enter the following menus: Powertrain / EV / Data List / Master Cylinder Control Torque.

      
      Powertrain > EV > Data List

      Tester Display
      Master Cylinder Control Torque

      
      Powertrain > EV > Data List

      Tester Display	Measurement Item	Normal Condition	Diagnostic Note
      Master Cylinder Control Torque	Braking torque equivalent to master cylinder brake fluid pressure Total braking torque	Brake pedal depressed: Changes with the brake pedal pressure	Master cylinder pressure sensor

      Result
      Result Proceed to Display changes according to brake pedal depression force. A Display does not change according to brake pedal depression force. B

   4. Turn the power switch off.

   
   

   B

   CHECK BRAKE BOOSTER PUMP ASSEMBLY Click here

   A

3. READ VALUE USING GTS (ACCEL PEDAL POSITION NO.1, ACCEL PEDAL POSITION NO.2)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Enter the following menus: Powertrain / EV / Data List / Accel Pedal Position No.1, Accel Pedal Position No.2.

      
      Powertrain > EV > Data List

      Tester Display
      Accel Pedal Position No.1
      Accel Pedal Position No.2

   4. Read the value of "Accel Pedal Position No.1" and "Accel Pedal Position No.2" displayed on the GTS.

      Standard
      Inspection Condition Specified Condition Accelerator pedal fully released → fully depressed Value (%) changes with accelerator pedal operation

   5. Turn the power switch off.

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

   OK

4. READ VALUE USING GTS (VEHICLE SPEED)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (READY).

   3. Enter the following menus: Powertrain / EV / Data List / Vehicle Speed.

      
      Powertrain > EV > Data List

      Tester Display
      Vehicle Speed

   4. Read the value of "Vehicle Speed" displayed on the GTS.

      Standard
      Inspection Condition Specified Condition Vehicle stopped 0 km/h (0 mph) Vehicle being driven at a constant speed (16 to 64 km/h (10 to 40 mph)) No large fluctuations in displayed speed

      CAUTION:

      Perform this road test only in an appropriate safe location, in accordance with all local laws.

      Tech Tips

      Data can be captured relatively easily by using the snapshot function in the Data List. Confirm the data after performing the drive test.

   5. Turn the power switch off.

      Result
      Proceed to OK NG

   
   

   NG

   GO TO METER / GAUGE SYSTEM Click here

   OK

5. READ VALUE USING GTS (FR, FL, RR, RL WHEEL SPEED)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (READY).

   3. Enter the following menus: Chassis / ABS/VSC/TRC / Data List / FR Wheel Speed, FL Wheel Speed, RR Wheel Speed and RL Wheel Speed.

      
      Chassis > ABS/VSC/TRAC > Data List

      Tester Display
      FR Wheel Speed
      FL Wheel Speed
      RR Wheel Speed
      RL Wheel Speed

   4. Read the value of "FR Wheel Speed", "FL Wheel Speed", "RR Wheel Speed" and "RL Wheel Speed" displayed on the GTS.

      Standard
      Inspection Condition Specified Condition Vehicle stopped 0 km/h (0 mph) Vehicle being driven at a constant speed (16 to 64 km/h (10 to 40 mph)) No large fluctuations in displayed speed

      CAUTION:

      Perform this road test only in an appropriate safe location, in accordance with all local laws.

      Tech Tips

      Data can be captured relatively easily by using the snapshot function in the Data List. Confirm the data after performing the drive test.

   5. Turn the power switch off.

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

   INSPECT SPEED SENSOR (FRONT OR REAR SPEED SENSOR) Click here