Dtc P0724 Brake Switch B Circuit High

Engine Hybrid System. Yaris. Ncp93, 131
1Nz-Fe Engine Control. Yaris. Ncp93, 131

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

CHECK STOP LIGHT SWITCH INSTALLATION

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)

DTC P0724 Brake Switch "B" Circuit High


DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling when brakes are suddenly applied while driving in lock-up condition.
When the brake pedal is depressed, this switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

DTC No.
DTC Detection Condition
Trouble Area
P0724
Stop light switch remains ON even when vehicle repeats 5 cycles of STOP (less than 3 km/h (1.86 mph)) and GO (30 km/h (18.65 mph) or more) (2 trip detection logic)
  1. Short in stop light switch signal circuit
  2. Stop light switch
  3. ECM

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains ON. When the stop light switch remains ON during "stop and go" driving, the ECM interprets this as a fault in the stop light switch and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 3 km/h (1.86 mph)) and go (30 km/h (18.65 mph) or more) 5 times during 2 driving cycles, in order to detect a malfunction.

MONITOR STRATEGY


Related DTCs
P0724: Stop light switch/Range check/Rationality
Required sensors/Components (Main)
Stop light switch
Required sensors/Components (Related)
Speed sensor
Frequency of Operation
Continuous
Duration
5 times
MIL Operation
2 driving cycles
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS

The stop light switch remains ON during GO and STOP 5 times.

GO and STOP are defined as follows;
Monitor runs whenever following DTCs not present
None
Battery voltage
8 V or higher
Starter
OFF
Ignition switch
ON
GO: Vehicle speed
30 km/h (18.65 mph) or more
STOP: Vehicle speed
Less than 3 km/h (1.86 mph)

TYPICAL MALFUNCTION THRESHOLDS


Stop light switch status
Stuck ON

CONFIRMATION DRIVING PATTERN


Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P0724 Brake Switch B Circuit High

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream on [A].
  6. Wait for 5 seconds.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
  8. Read pending DTCs.
    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. If a pending DTC is not output, perform the following procedure.
  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  10. Input the DTC: P0724.
  11. Check the DTC judgment result.

    Techstream Display
    		Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
    3. If the judgment result shows INCOMPLETE or N/A, perform steps [C] through [E].
  12. Start the engine [C].
  13. Accelerate the vehicle to 30 km/h (18.65 mph) or more, depress the brake pedal and decelerate the vehicle to 3 km/h (1.86 mph) or less [D]. Repeat step [D] 5 times.
    CAUTION:
    When performing the confirmation driving pattern, obey all speed limits and traffic laws.
  14. Check the DTC judgment result [E].
  15. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0QGX.html).
    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.

WIRING DIAGRAM


Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P0724 Brake Switch B Circuit High


INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
  1. Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
  2. Using the Techstream, the Data List item "Stop Light Switch" and "ST1" can be read (YARIS_NCP93 RM000000XCT0KEX_03.html).
1.READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Read the values displayed on the Techstream.


OK:

Item
Measurement Item: Range (display)
Normal Condition
Stop Light Switch
Stop light switch status:
ON or OFF
  1. ON: Brake pedal is depressed
  2. OFF: Brake pedal is released


NG
Go to step 2
OK

CHECK FOR INTERMITTENT PROBLEMS (YARIS_NCP93 RM000000PDQ0NOX.html)

2.CHECK STOP LIGHT SWITCH INSTALLATION

  1. Check the stop light switch installation (YARIS_NCP93 RM000001DKQ022X.html).

    OK:
    Stop light switch is installed correctly.
Result
Result
Proceed to
OK
A
NG
B


B
SECURELY REINSTALL STOP LIGHT SWITCH (YARIS_NCP93 RM000001DKQ022X.html)
A


3.INSPECT STOP LIGHT SWITCH ASSEMBLY
Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P0724 Brake Switch B Circuit High

  1. Remove the stop light switch assembly.

  1. Check the resistance.

    Standard resistance:
    Tester Connections
    		Switch Positions
    		Specified Conditions
    1 - 2
    		Switch pin released
    		Below 1 Ω
    Switch pin pushed in
    		10 kΩ or higher
    3 - 4
    		Switch pin released
    		10 kΩ or higher
    Switch pin pushed in
    		Below 1 Ω

  1. Reinstall the stop light switch assembly.

Result
Result
Proceed to
OK
A
NG
B


B
REPLACE STOP LIGHT SWITCH ASSEMBLY (YARIS_NCP93 RM000001DKT021X.html)
A


4.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)


    Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan). Dtc P0724 Brake Switch B Circuit High

  1. Disconnect the A21 ECM connector.

  1. Disconnect the A13 stop light switch connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    STP (A21-36) - Stop light switch (A13-1)
    		Below 1 Ω
    ST1- (A21-35) - Stop light switch (A13-4)
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    STP (A21-36) or Stop light switch (A13-1) - Body ground
    		10 kΩ or higher
    ST1- (A21-35) or Stop light switch (A13-4) - Body ground

  1. Reconnect the ECM connector.

  1. Reconnect the stop light switch connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (YARIS_NCP93 RM000001CN002AX.html)