Dtc P0504 Brake Switch A / B Correlation

Engine. Camry. Acv40 Gsv40
2Gr-Fe Engine Control System. Camry. Acv40 Gsv40

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK STOP LIGHT (OPERATION OF STOP LIGHT)

READ VALUE USING INTELLIGENT TESTER (STP SIGNAL AND ST1 - VOLTAGE)

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK ECM (STP, ST1 - VOLTAGE)

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

DTC P0724 Brake Switch "B" Circuit High


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 sets the DTC.

HINT:
The normal conditions are as shown in the table below. The signals can be read using an intelligent tester.

Signal
Brake Pedal Released
In Transition
Brake Pedal Depressed
STP
OFF
ON
ON
ST1-
ON
ON
OFF

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) Ignition switch to the ON position
(b) Brake pedal released
(c) STP signal OFF when ST1- signal OFF
  1. Short in stop light switch signal circuit
  2. Stop light switch
  3. ECM
P0724
The stop light switch remains ON even when the vehicle is driven in a STOP (less than 2 mph (3 km/h)) and GO (19 mph (30 km/h) or more) fashion 5 times. (2 trip detection logic)
  1. Short in stop light switch signal circuit
  2. Stop light switch
  3. ECM

WIRING DIAGRAM


Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System. Dtc P0504 Brake Switch A / B Correlation


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (CAMRY_ACV40 RM000000PDS01FX.html).
1.CHECK STOP LIGHT (OPERATION OF STOP LIGHT)

  1. Check whether the stop lights turn on and off normally when the brake pedal is depressed and released.

    OK:
    Stop lights turn ON when brake pedal is depressed.


NG
REPAIR OR REPLACE STOP LIGHT SWITCH CIRCUIT
OK


2.READ VALUE USING INTELLIGENT TESTER (STP SIGNAL AND ST1 - VOLTAGE)


    Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System. Dtc P0504 Brake Switch A / B Correlation

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position and turn the tester on.

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

  1. Check the STP signal when the brake pedal is depressed and released.

    OK:
    Brake Pedal Operation
    		Specified Condition
    Depressed
    		STP signal ON
    Released
    		STP signal OFF

  1. Enter the following menus: Powertrain / Engine / Data List / ST1.

  1. Check the ST1 signal when the brake pedal is depressed and released.

    OK:
    Brake Pedal Operation
    		Specified Condition
    Depressed
    		ST1 signal OFF
    Released
    		ST1 signal ON


OK
CHECK FOR INTERMITTENT PROBLEMS
NG


3.INSPECT STOP LIGHT SWITCH ASSEMBLY


    Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System. Dtc P0504 Brake Switch A / B Correlation

  1. Remove the stop light switch assembly.

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

    Standard resistance:
    Switch Position
    		Tester Connection
    		Specified Condition
    Switch pin free
    		1 - 2
    		Below 1 Ω
    Switch pin free
    		3 - 4
    		10 kΩ or higher
    Switch pin pushed in
    		1 - 2
    		10 kΩ or higher
    Switch pin pushed in
    		3 - 4
    		Below 1 Ω

  1. Reinstall the stop light switch assembly.



NG
REPLACE STOP LIGHT SWITCH ASSEMBLY (CAMRY_ACV40 RM000001WI400NX.html)
OK


4.CHECK ECM (STP, ST1 - VOLTAGE)


    Camry. Acv40 Gsv40.2Gr-Fe Engine Control System.Sfi System. Dtc P0504 Brake Switch A / B Correlation

  1. Disconnect the A24 (*1) or A55 (*2) ECM connector.

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

    Standard voltage:
    Tester Connection
    		Brake Pedal Operation
    		Specified Condition
    STP (A24-36)*1 - Body ground
    		Depressed
    		9 to 14 V
    STP (A55-36)*2 - Body ground
    		Depressed
    		9 to 14 V
    STP (A24-36)*1 - Body ground
    		Released
    		0 to 3 V
    STP (A55-36)*2 - Body ground
    		Released
    		0 to 3 V
    ST1- (A24-35)*1 - Body ground
    		Depressed
    		0 to 3 V
    ST1- (A55-35)*2 - Body ground
    		Depressed
    		0 to 3 V
    ST1- (A24-35)*1 - Body ground
    		Released
    		9 to 14 V
    ST1- (A55-35)*2 - Body ground
    		Released
    		9 to 14 V
    HINT:
    *1: RHD
    *2: LHD


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (CAMRY_ACV40 RM0000022NT00OX.html)