Dtc P0504 Brake Switch A / B Correlation

Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
1Ur-Fe Engine Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING GTS (STOP LIGHT SWITCH)

INSPECT STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)

INSPECT STOP LIGHT SWITCH ASSEMBLY

INSPECT ECM (STP AND ST1 - VOLTAGE)

DTC P0504 Brake Switch "A" / "B" Correlation


DESCRIPTION

The stop light switch is 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. If signals which indicate the brake pedal is being depressed and released are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and stores the DTC.

HINT:
The normal signal conditions are as shown in the table below.

Signal (ECM Terminal)
Brake Pedal Released
In Transition
Brake Pedal Depressed
STP
OFF
ON
ON
ST1-
ON
ON
OFF
  1. [OFF] denotes ground potential.
  2. [ON] denotes battery potential (+B).
  3. On the GTS, the Data List items Stop Light Switch and ST1 are both ON when the brake pedal is depressed because the characteristics of ST1 indication are the opposite of the characteristics of Stop Light Switch indication.

DTC No.
DTC Detection Condition
Trouble Area
P0504
Conditions (a), (b) and (c) continue for 0.5 seconds or more
(1 trip detection logic):
(a) Engine switch is on (IG).
(b) Brake pedal is released.
(c) STP signal is OFF when the ST1- signal is OFF.
  1. Short in stop light switch signal circuit
  2. STOP fuse
  3. IGN fuse
  4. Stop light switch assembly
  5. ECM

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.1Ur-Fe Engine Control.Sfi System. Dtc P0504 Brake Switch A / B Correlation


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses of circuits related to this system before performing the following inspection procedure.
HINT:
  1. 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
  2. STP signal conditions can be checked using the GTS.
    1. Connect the GTS to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the GTS on.
    4. Enter the following menus: Powertrain / Engine and ECT / All Data / Stop Light Switch.
    5. Check the STP signal when the brake pedal is depressed and released.

Brake Pedal Operation
Specified Condition
Depressed
STP signal ON
Released
STP signal OFF
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 / All Data / Stop Light Switch.

  1. Read the value displayed on the GTS.

    Standard:

    Condition
    		Specified Condition
    Brake pedal depressed
    		STP signal ON
    Brake pedal released
    		STP signal OFF


NG
Go to step 2
OK

CHECK FOR INTERMITTENT PROBLEMS (Click here)

2.INSPECT STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)
Land Cruiser. Urj200, 202 Grj200 Vdj200.1Ur-Fe Engine Control.Sfi System. Dtc P0504 Brake Switch A / B Correlation

  1. Disconnect the stop light switch connector.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A30-2 - Body ground
    		Always
    		11 to 14 V
    A30-4 - Body ground
    		Engine switch on (IG)
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Stop Light Switch)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - STOP LIGHT SWITCH)
OK


3.INSPECT STOP LIGHT SWITCH ASSEMBLY

  1. Inspect the stop light switch assembly (Click here).



NG
REPLACE STOP LIGHT SWITCH ASSEMBLY (Click here)
OK


4.INSPECT ECM (STP AND ST1 - VOLTAGE)
Land Cruiser. Urj200, 202 Grj200 Vdj200.1Ur-Fe Engine Control.Sfi System. Dtc P0504 Brake Switch A / B Correlation

  1. Disconnect the ECM connector.

  1. Turn the engine switch on (IG).

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

    Standard Voltage:
    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    A52-35 (ST1-) - Body ground
    		Brake pedal released
    		7.5 to 14 V
    Brake pedal depressed
    		Below 1.5 V
    A52-36 (STP) - Body ground
    		Brake pedal released
    		Below 1.5 V
    Brake pedal depressed
    		7.5 to 14 V
    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    A38-35 (ST1-) - Body ground
    		Brake pedal released
    		7.5 to 14 V
    Brake pedal depressed
    		Below 1.5 V
    A38-36 (STP) - Body ground
    		Brake pedal released
    		Below 1.5 V
    Brake pedal depressed
    		7.5 to 14 V
    Text in Illustration
    *A
    		for RHD
    *B
    		for LHD
    *a
    		Depressed
    *b
    		Released
    *c
    		Component with harness connected
    (ECM)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)