DTC P0724 Brake Switch "B" Circuit High 1GR-FE

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY)

DTC P0724 Brake Switch "B" Circuit High

Description DTC P0724

The stop light switch assembly is a duplex system that transmits 2 signals: STP and ST1-. These 2 signals are used by the ECM to monitor whether or not the brake system is working properly.

The purpose of this circuit is to prevent the engine from stalling while driving with the lock-up torque converter clutch on when the brakes are suddenly applied.

When the brake pedal is depressed, the stop light switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

DTC Code	DTC Detection Condition	Trouble Area
P0724	The stop light switch remains on even when vehicle is driven in a GO (30 km/h (18.63 mph) or more) and STOP (less than 3 km/h (1.86 mph)) pattern 5 times (2 trip detection logic).	Short in stop light switch signal circuit Stop light switch assembly ECM

Wiring diagram

Refer to DTC P0504.

Inspection procedure

HINT:

1. Using the intelligent tester to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. Reading the Data List information early in troubleshooting is one way to save diagnostic time.
2. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1.READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch to ON.

3. Turn the tester on.

4. Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch.

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

   OK:

   Brake Pedal	Display
   Released	OFF
   Depressed	ON

NG	Go to step 2

OK
CHECK FOR INTERMITTENT PROBLEMS

2.INSPECT STOP LIGHT SWITCH ASSEMBLY

1. Disconnect the stop light switch assembly connector.

2. Remove the stop light switch assembly.

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

   Standard Resistance:

   Tester Connection	Switch Position	Specified Condition
   1 - 2	Switch pin not pushed	Below 1 ?
   	Switch pin pushed	10 k? or higher
   3 - 4	Switch pin not pushed	10 k? or higher
   	Switch pin pushed	Below 1 ?

4. Reinstall the stop light switch assembly.

5. Reconnect the stop light switch assembly connector.

NG	REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

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

1. Disconnect the ECM connector.

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage:

   for LHD

   Tester Connection	Condition	Specified Condition
   A38-36 (STP) - Body ground	Brake pedal depressed	11 to 14 V
   	Brake pedal released	0 to 3 V

   for RHD

   Tester Connection	Condition	Specified Condition
   A52-36 (STP) - Body ground	Brake pedal depressed	11 to 14 V
   	Brake pedal released	0 to 3 V

3. Reconnect the ECM connector.

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE ECM