Dtc P0724 Brake Switch B Circuit High


DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING GTS (STOP LIGHT SWITCH)

CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION

CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH)

INSPECT STOP LIGHT SWITCH ASSEMBLY

DTC P0724 Brake Switch "B" Circuit High


DESCRIPTION

DESCRIPTION The stop light switch assembly is part of a duplex system that transmits two signals: STP and ST1-. These two 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 assembly is remaining on. When the stop light switch assembly remains on during "STOP and GO" driving, the ECM interprets this as a fault in the stop light switch assembly. The ECM will illuminate the MIL and store this DTC.

P0724
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
Accelerate the vehicle to 30 km/h (19 mph) or more, depress the brake pedal and decelerate the vehicle to 3 km/h (1.8 mph) or less 5 times.
Stop light switch remains on even when the 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).
  1. Short in stop light switch signal circuit
  2. Stop light switch assembly
  3. 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 (18.63 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 (LandCruiser RM000000XCT17DX_02.html).

INSPECTION PROCEDURE

NOTICE:
After replacing the ECM, the new ECM needs registration (LandCruiser RM0000012XK0AVX.html) and initialization (LandCruiser RM000000TIN08IX.html).
HINT:
Read freeze frame data using the GTS. Freeze frame data records 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, and other data from the time the malfunction occurred.
1.READ VALUE USING GTS (STOP LIGHT SWITCH)

  1. Connect the GTS to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the GTS on.

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

  1. Read the value displayed on the GTS 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 (LandCruiser RM000000PDQ1A0X.html)

2.CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION

  1. Check the stop light switch assembly installation.

    OK:
    Stop light switch assembly is installed correctly.


NG
SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY
OK


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

  1. Disconnect the stop light switch assembly connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A85-2 (L) - G185-13 (STP)
    		Always
    		Below 1 Ω
    A85-4 (L) - G185-12 (ST1-)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT STOP LIGHT SWITCH ASSEMBLY

  1. Inspect the stop light switch assembly (LandCruiser RM000003QJR00YX.html).



NG
REPLACE STOP LIGHT SWITCH ASSEMBLY (LandCruiser RM000003QJT01GX.html)
OK

REPLACE ECM (LandCruiser RM0000013Z002DX.html)