Land Cruiser URJ200 URJ202 GRJ200 VDJ200 - 3UR-FE ENGINE CONTROL

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK 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 the 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 ReleasedIn TransitionBrake Pedal Depressed
STPOFFONON
ST1-ONONOFF
[OFF] denotes ground potential.
[ON] denotes battery potential (+B).
On the GTS, both the Data List items Stop Light Switch and ST1 are ON when the brake pedal is depressed because the ST1 indication characteristic is opposite to the Stop Light Switch indication.
DTC CodeDTC Detection ConditionTrouble Area
P0504Conditions (a), (b) and (c) continue for 0.5 seconds or more (1 trip detection logic):
(a) The engine switch is on (IG).
(b) The brake pedal is released.
(c) The STP signal is OFF when the ST1- signal is OFF.
Short in stop light switch signal circuit
STOP fuse
IGN fuse
Stop light switch
ECM

WIRING DIAGRAM

Dtc P0504 Brake Switch A / B Correlation. 3UR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

INSPECTION PROCEDURE

  • NOTICE:
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  • 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, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
STP signal conditions can be checked using the GTS.
Connect the tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Stop Light Switch and ST1.
Check the Data List indication when the brake pedal is depressed and released.
Brake Pedal OperationStop Light SwitchST1
DepressedONON
ReleasedOFFOFF
1.CHECK STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)
Dtc P0504 Brake Switch A / B Correlation. 3UR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Disconnect the A30 stop light switch connector.

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

  • Standard Voltage:
  • Tester ConnectionSwitch ConditionSpecified Condition
    A30-2 - Body groundAlways11 to 14 V
    A30-4 - Body groundEngine switch on (IG)11 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
2.INSPECT STOP LIGHT SWITCH ASSEMBLY
Dtc P0504 Brake Switch A / B Correlation. 3UR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Remove the stop light switch.

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

  • Standard Resistance:
  • Tester ConnectionSwitch ConditionSpecified Condition
    1 - 2Pin not pushedBelow 1 Ω
    Pin pushed10 kΩ or higher
    3 - 4Pin not pushed10 kΩ or higher
    Pin pushedBelow 1 Ω
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY ()
OK
3.CHECK ECM (STP AND ST1 - VOLTAGE)
Dtc P0504 Brake Switch A / B Correlation. 3UR-FE ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Disconnect the A38 ECM connector.

Turn the engine switch on (IG).

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

  • Standard Voltage:
  • Tester ConnectionConditionSpecified Condition
    A38-35 (ST1-) - Body groundBrake pedal released11 to 14 V
    Brake pedal depressed0 to 3 V
    A38-36 (STP) - Body groundBrake pedal released0 to 3 V
    Brake pedal depressed11 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE ECM ()
3UR-FE ENGINE CONTROL
Land Cruiser URJ200 URJ202 GRJ200 VDJ200
SFI SYSTEM