DTC P0724 Brake Switch "B" Circuit High

DESCRIPTION

The stop light switch is part of 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.

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0724	Stop light switch remains on even when the vehicle is driven in a GO (30 km/h (18.65 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

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC. The vehicle must GO (30 km/h (18.65 mph) or more) and STOP (less than 3 km/h (1.86 mph)) 5 times for 2 driving cycles in order for the DTC to be stored.

WIRING DIAGRAM

Refer to DTC P0504 ().

INSPECTION PROCEDURE

HINT:

Using the GTS to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

Warm up the engine.

Turn the ignition switch off.

Connect the GTS to the DLC3.

Turn the ignition switch to ON.

Turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Data List.

According to the display on the GTS, read the Data List.

GTS Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Stop Light Switch	Stop light switch status/ON or OFF	Brake pedal depressed: ON Brake pedal released: OFF	-

1.INSPECT STOP LIGHT SWITCH ASSEMBLY

Inspect the stop light switch assembly ().

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY ()

OK

2.CHECK HARNESS AND CONNECTOR (ECM - BATTERY)

Dtc P0724 Brake Switch B Circuit High. 1GR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Disconnect the ECM connector.

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 7.5 to 14 V
A38-36 (STP) - Body ground Brake pedal released Below 1.5 V
for RHD
Tester Connection Condition Specified Condition
A52-36 (STP) - Body ground Brake pedal depressed 7.5 to 14 V
A52-36 (STP) - Body ground Brake pedal released Below 1.5 V

for LHD
Tester Connection	Condition	Specified Condition
A38-36 (STP) - Body ground	Brake pedal depressed	7.5 to 14 V
A38-36 (STP) - Body ground	Brake pedal released	Below 1.5 V

for RHD
Tester Connection	Condition	Specified Condition
A52-36 (STP) - Body ground	Brake pedal depressed	7.5 to 14 V
A52-36 (STP) - Body ground	Brake pedal released	Below 1.5 V

Text in Illustration
*A	for LHD
*B	for RHD
*a	Brake Pedal Depressed
*b	Brake Pedal Released
*c	Front view of wire harness connector (to ECM)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

REPLACE ECM ()

1GR-FE ENGINE CONTROL

Land Cruiser URJ200 URJ202 GRJ200 VDJ200

SFI SYSTEM