СИСТЕМА SFI Brake Override System

DESCRIPTION

When the vehicle is being driven, depressing the accelerator pedal sensor assembly 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:
- When the accelerator pedal and brake pedal are depressed.
  
  Note
  
  The vehicle may not enter the brake override system control due to the relation of the accelerator pedal angle and the vehicle's speed.

Items Controlled:
- When the vehicle speed is extremely low, the accelerator opening value used when controlling the engine is reduced more than normal.
  
  Tech Tips
  
  During control, the Accelerator Position value in the Data List will be lower than normal.
- When the vehicle speed is not extremely low, the accelerator opening value is forcibly lowered to a fixed value.
  Tech Tips
  - During control, the Accelerator Position value in the Data List is forcibly reduced to a specified value regardless of the actual accelerator opening value (Accel Sens. No. 1 Volt %).
  - During brake override system control, the operation indicator is displayed on the meter.

Deactivation Conditions:
- When the brake pedal or the accelerator pedal returns to some degree.

CAUTION / NOTICE / HINT

Inspection Method
Example:

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 the engine speed decreases to 1000 rpm when the brake pedal is depressed, then the brake override system has been activated.

CAUTION:

When carrying out the inspection, use a place where you are able to carry it out safely and also pay close attention to your surroundings.

Also, when driving make absolutely sure that all road traffic laws, such as speed limits, are observed.

Tech Tips

Under normal conditions, the Accelerator Position value changes in response to the Accel Sens. No.1 Volt % value. For more information on the numerical values, refer to the Data List.

Click here
If the Accelerator Position and Accel Sens. No.1 Volt % values in the Data List diverge and the Accelerator Position value in the Data List is fixed even though Accel Sens. No.1 Volt % is changing, check that this control is activated (use the GTS data saving function to record data while driving the vehicle and then confirm it after driving is completed).

Note

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 loss of torque after the accelerator and brake pedals have both been intentionally depressed, explain to the customer that this is not a malfunction, and that the customer should avoid depressing both the accelerator and brake pedals at the same time.

Example: While operating the accelerator pedal, the customer uses their left foot to operate the brake pedal.

PROCEDURE

CHECK DTC OUTPUT

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: System Select / Health Check.

Check the DTCs.

Result

Result	Proceed to
DTCs are not output	A
DTCs are output	B

GO TO DTC CHART

READ VALUE USING GTS (MASTER CYLINDER PRESSURE)

Connect the GTS to the DLC3.
Start the engine and turn the GTS on.
Enter the following menus: Chassis / ABS/VSC/TRC / Data List / Master Cylinder Pressure.

Chassis > ABS/VSC/TRC > Data List

Tester Display

Master Cylinder Pressure
Read the value displayed on the GTS.

Standard

0 to 1.76 Mpa (Brake pedal released).

Tester Display
Master Cylinder Pressure

Standard
0 to 1.76 Mpa (Brake pedal released).

Check that the brake fluid pressure value of the "Master Cylinder Pressure" observed on the GTS changes when the brake pedal is depressed.

OK
When the pedal is depressed, the pressure displayed on the GTS increases.

Result

Proceed to
OK
NG

CHECK BRAKE ACTUATOR ASSEMBLY Click here

READ VALUE USING GTS (STOP LIGHT SWITCH AND ST1)

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Stop Light Switch and ST1.

Powertrain > Engine > Data List

Tester Display
Stop Light Switch
ST1

Check the Data List indication when the brake pedal is depressed and released.

GTS Display	Condition	Specified Condition
Stop Light Switch	Brake pedal released	OFF
Stop Light Switch	Brake pedal depressed	ON
ST1	Brake pedal released	OFF
ST1	Brake pedal depressed	ON

Result

Proceed to
OK
NG

INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

INSPECT BRAKE PEDAL SUPPORT ASSEMBLY

Inspect and adjust the brake pedal support assembly.

Click here

Tech Tips

If the stop light switch assembly turns on too late, the start of brake override system control may be delayed; if it turns ON too soon, brake override system control may begin too early, so conduct inspection of the brake pedal support assembly and stop light switch assembly.

Result

Proceed to
OK
NG

REPAIR OR REPLACE BRAKE PEDAL SUPPORT ASSEMBLY Click here

READ VALUE USING GTS (ACCELERATOR PEDAL SENSOR)

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %.

Powertrain > Engine > Data List

Tester Display
Accel Sens. No.1 Volt %
Accel Sens. No.2 Volt %

Read the value displayed on the GTS.

GTS Display

Condition

Specified Condition

Accel Sens. No.1 Volt %

Accelerator Pedal

Released → Depressed → Released

Values smoothly change following accelerator pedal operation

Accel Sens. No.2 Volt %

Tech Tips

For numerical values of Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %, refer to the Data List.

Click here

Result

Proceed to
OK
NG

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

READ VALUE USING GTS (VEHICLE SPEED)

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Vehicle Speed.

Powertrain > Engine > Data List

Tester Display

Vehicle Speed

Tester Display
Vehicle Speed

Read the value displayed on the GTS.

Standard

GTS Display	Condition	Specified Condition
Vehicle Speed	Vehicle stopped, engine running	0 km/h (0 mph)
Vehicle Speed	Vehicle being driven at constant speed between 16.1 to 64.4 km/h (10 to 40 mph)	No large fluctuations when driving at a constant speed

CAUTION:

When performing a driving test, obey all speed limits and traffic 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.

Result

Proceed to
OK
NG

GO TO METER / GAUGE SYSTEM (SPEED SIGNAL CIRCUIT) Click here

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Start the engine.

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/TRC > Data List

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

Read the value displayed on the GTS.

Standard

GTS Display

Condition

Specified Condition

FR Wheel Speed

FL Wheel Speed

RR Wheel Speed

RL Wheel Speed

Vehicle stopped, engine running

0 km/h (0 mph)

Vehicle being driven at constant speed between 16.1 to 64.4 km/h (10 to 40 mph)

No large fluctuations when driving at a constant speed

CAUTION:

When performing a driving test, obey all speed limits and traffic 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.

Result

Proceed to
OK
NG

END

INSPECT FRONT OR REAR SPEED SENSOR