Dtc P0724 Brake Switch B Circuit High


DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

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

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 (18.63 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.

MONITOR STRATEGY


Required sensors/Components
Stop light switch assembly, Vehicle speed sensor
Frequency of operation
Continuous

CONFIRMATION DRIVING PATTERN


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.2Tr-Fe Engine Control.Sfi System. Dtc P0724 Brake Switch B Circuit High

  1. Connect the GTS to the DLC3.
  2. Turn the ignition switch to ON and turn the GTS on.
  3. Clear the 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 GTS on [A].
  6. Wait 5 seconds.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
  8. Read the 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.

    GTS 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 (19 mph) or more, and then depress the brake pedal and decelerate the vehicle to 3 km/h (1.8 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].

WIRING DIAGRAM

Refer to DTC P0504 (LandCruiser RM000000XCT16LX_02.html).

INSPECTION PROCEDURE

HINT:
Using the GTS, the Data List item "Stop Light Switch" can be read.

Item
Measurement Item/
Range
Normal Condition
Diagnostic Note
Stop Light Switch
Stop light switch status/
ON or OFF
  1. Brake pedal depressed: ON
  2. Brake pedal released: OFF
-
1.READ VALUE USING GTS (STOP LIGHT SWITCH)

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  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

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) - G180-10 (STP)
    		Always
    		Below 1 Ω
    A85-4 (L) - G180-11 (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 RM000000VW203EX.html)