Brand:

Toyota

Model Name:

Yaris NCP90 91 92 93

Manual:

Repair Manual

Section:

1Nz-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Wiring diagram

  3. Inspection procedure

  4. Read value using intelligent tester (stop light switch)

  5. Check stop light switch installation

  6. Read value using intelligent tester (stop light switch)

  7. Inspect stop light switch assembly

  8. Check harness and connector (stop light switch - ecm)

  9. Check harness and connector (stop light control relay - stop light switch)

DTC P0724 Brake Switch "B" Circuit High


​

DESCRIPTION

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

DTC No.
DTC Detection Conditions
Trouble Areas
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. Stop light control relay*
  4. ECM
  1. *: for Hatchback

WIRING DIAGRAM


Connect an intelligent tester to the DLC3. Yaris


Connect an intelligent tester to the DLC3. Yaris


INSPECTION PROCEDURE

HINT:
Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. 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.
1.READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

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

  1. Read the value displayed on the tester when the brake pedal is depressed and released.

OK:
Brake Pedal
Display
Released
OFF
Depressed
ON


NGnext
Go to step 2
OK
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CHECK FOR INTERMITTENT PROBLEMS (Click here)

2.CHECK STOP LIGHT SWITCH INSTALLATION

  1. Check the stop light switch installation (Click here).

    OK:
    Stop light switch is installed correctly.
    Result:
    Result
    		Proceed To
    OK (Hatchback)
    		A
    OK (Sedan)
    		B
    NG
    		C


Bnext
Go to step 4

Cnext
SECURELY REINSTALL STOP LIGHT SWITCH
A
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3.READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

  1. Disconnect the stop light control relay connector.

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

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

  1. Read the value displayed on the tester when the brake pedal is depressed and released.

OK:
Brake Pedal
Display
Released
OFF
Depressed
ON

  1. Reconnect the stop light control relay connector.



NGnext
Go to step 4
OK
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REPLACE STOP LIGHT CONTROL RELAY

4.INSPECT STOP LIGHT SWITCH ASSEMBLY
Remove the stop light switch assembly. Yaris

  1. Remove the stop light switch assembly.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Switch Position
    		Specified Condition
    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.



NGnext
REPLACE STOP LIGHT SWITCH ASSEMBLY (Click here)
OK
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5.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)
  1. Disconnect the ECM connector. Yaris

  2. Disconnect the ECM connector.

  1. Disconnect the stop light switch connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    A21-36 (STP) - A13-1
    		Always
    		Below 1 Ω
    A21-35 (ST1-) - A13-4
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    A21-36 (STP) or A13-1 - Body ground
    		Always
    		10 kΩ or higher
    A21-35 (ST1-) or A13-4 - Body ground
    		Always
    		10 kΩ or higher
    Result:
    Result
    		Proceed To
    OK (Hatchback)
    		A
    OK (Sedan)
    		B
    NG
    		C

  1. Reconnect the ECM connector.

  1. Reconnect the stop light switch connector.



Bnext
REPLACE ECM (Click here)

Cnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
A
next down

6.CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - STOP LIGHT SWITCH)
  1. Disconnect the stop light control relay connector. Yaris

  2. Disconnect the stop light control relay connector.

  1. Disconnect the stop light switch connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    J55-6 (+B) - A13-2
    		Always
    		Below 1 Ω
    J55-2 (STP) - A13-1
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    J55-6 (+B) or A13-2 - Body ground
    		Always
    		10 kΩ or higher
    J55-2 (STP) or A13-1 - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the stop light control relay connector.

  1. Reconnect the stop light switch connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM (Click here)