SFI SYSTEM 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 %).

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 in the Data List and Accel Sens. No. 1 Volt % values diverge and the Accelerator Positon value in the Data List is fixed even though Accel Sens. No. 1 Volt % is changing, check that this control is activated (use the Techstream 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 intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Utility / All Codes.

Check DTCs.

Result

Result	Proceed to
No DTC output	A
DTC output	B

GO TO DTC CHART Click here

READ VALUE USING INTELLIGENT TESTER (MASTER CYLINDER SENSOR)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the intelligent tester on.
Enter the following menus: Chassis / ABS/VSC/TRC / Data List / Master Cylinder Sensor.

Read the value displayed on the intelligent tester.

Tester Display	Condition	Specified Condition
Master Cylinder Sensor	Master cylinder pressure sensor reading/ Min.: 0.00 V, Max.: 5.00 V	Brake pedal released: 0.30 to 0.90 V Reading increases when brake pedal is depressed

Tester Display

Condition

Specified Condition

Master Cylinder Sensor

Master cylinder pressure sensor

reading/

Min.: 0.00 V, Max.: 5.00 V

Brake pedal released: 0.30 to 0.90 V
Reading increases when brake pedal is depressed

Check that the brake fluid pressure value of the "Master Cylinder Sensor" observed on the intelligent tester changes when the brake pedal is depressed.

OK

When the pedal is depressed, the voltage displayed on the intelligent tester increases.

OK
When the pedal is depressed, the voltage displayed on the intelligent tester increases.

CHECK BRAKE ACTUATOR ASSEMBLY

READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH AND ST1)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch and ST1.

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

Tester 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

INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

INSPECT BRAKE PEDAL HEIGHT

Inspect the brake pedal height.

Brake Pedal	See page
for RHD	Click here
for LHD	Click here

Tech Tips

If the stop light switch 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 and stop light switch assembly.

Result

Result	Proceed to
OK	A
NG (for RHD)	B
NG (for LHD)	C

ADJUST BRAKE PEDAL Click here

READ VALUE USING INTELLIGENT TESTER (ACCELERATOR PEDAL POSITION SENSOR)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sens. No. 1 Volt % and Accel Sens. No. 2 Volt %.

Read the value displayed on the tester.

Tester 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.

REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

READ VALUE USING INTELLIGENT TESTER (VEHICLE SPEED)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the intelligent tester on.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / Vehicle Speed.

Read the value displayed on the tester.

Standard

Tester Display	Condition	Specified Condition
Vehicle Speed	Vehicle stopped, engine running	0 km/h (0 mph)
Vehicle Speed	Vehicle running 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 the confirmation driving pattern, 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.

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

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester 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.

Read the value displayed on the ester.

Standard

Tester 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 running 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 the confirmation driving pattern, 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.

END

INSPECT FRONT OR REAR SPEED SENSOR