SFI SYSTEM Brake Override System
| DTC Code | DTC Name |
|---|---|
| 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:
Vehicle is running at or above the specified speed.
When the accelerator pedal and brake pedal are depressed.
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:
Driving torque is restricted.
During brake override system control, the value for the accelerator pedal angle (which is used for engine control) is forcibly reduced to a specified value. For this reason, the Data List value for Accelerator Position will be replaced with a specified value regardless of the actual accelerator pedal angle (Accel Sens. No.1 Volt %, Accel Sens. No.2 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.
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.
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.
If the Accelerator Position in the Data List and Accel Sens. No. 1 Volt % values 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).
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 ignition switch to ON and turn the GTS on.
Enter the following menus: System Select / Health Check.
Check the DTCs.
Result
Result
Proceed to
DTC is not output
A
DTCs are output
B
B GO TO DTC CHART
READ VALUE USING GTS (MASTER CYLINDER PRESSURE)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Start the engine.
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.
GTS Display
Measurement Item/Range
Normal Condition
Master Cylinder Pressure
Master cylinder pressure sensor reading/
Min.: 0.00 MPa, Max.: 23.28 MPa
Brake pedal released: 0.00 to 1.76 MPa
Reading increases when brake pedal is depressed
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
NG CHECK BRAKE ACTUATOR ASSEMBLY
READ VALUE USING GTS (STOP LIGHT SWITCH AND ST1)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Stop Light Switch and ST1.
Powertrain > Engine and ECT > Data List
Tester Display
Stop Light Switch
ST1
Check the Data List indication when the brake pedal is depressed and released.
OK
GTS Display
Condition
Specified Condition
Stop Light Switch
Brake pedal released
OFF
Brake pedal depressed
ON
ST1
Brake pedal released
OFF
Brake pedal depressed
ON
Result
Proceed to
OK
NG
INSPECT BRAKE PEDAL SUPPORT ASSEMBLY
Inspect and adjust the brake pedal support assembly.
Tip: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
NG REPAIR OR REPLACE BRAKE PEDAL SUPPORT ASSEMBLY
READ VALUE USING GTS (ACCELERATOR PEDAL SENSOR)
Connect the GTS to the DLC3.
Turn the ignition switch to ON 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 and ECT > Data List
Tester Display
Accel Sens. No.1 Volt %
Accel Sens. No.2 Volt %
Read the value displayed on the GTS.
OK
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 %
Tip:For numerical values of Accel Sens. No.1 Volt % and Accel Sens. No.2 Volt %, refer to the Data List.
Result
Proceed to
OK
NG
READ VALUE USING GTS (VEHICLE SPEED)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Vehicle Speed.
Powertrain > Engine and ECT > Data List
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 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.
Tip: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
READ VALUE USING GTS (FR, FL, RR, RL WHEEL SPEED)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Start the engine.
Enter the following menus: Chassis / ABS/VSC/TRAC / 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
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 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.
Tip: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
OK END
NG INSPECT FRONT OR REAR SPEED SENSOR