ECD SYSTEM(w/o DPF), Diagnostic DTC:P0504

DTC Code DTC Name
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 that 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.

Tech Tips

The normal 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

  • [OFF] denotes ground potential.

  • [ON] denotes battery potential (+B).

  • On the intelligent tester, 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.

P0504
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Release and depress brake pedal with ignition switch ON.

  • Conditions (a), (b) and (c) continue for 5.0 seconds or more:


    1. Ignition switch ON

    2. Brake pedal depressed

    3. STP signal off when ST1 signal off

  • (2 trip detection logic)

  • Short in stop light switch signal circuit

  • Stop light switch assembly

  • ECM
Related Data List
DTC No. Data List
P0504 Stop Light Switch

WIRING DIAGRAM

A01VF9FE02
A01VIRWE02

CAUTION / NOTICE / HINT

Note


  • When replacing the ECM, the ECM needs Registration and Initialization Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.

  • Read freeze frame data using the intelligent tester. 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.

  • Stop light switch assembly conditions can be checked using the intelligent tester.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch and ST1.

    4. Check Stop Light Switch when the brake pedal is depressed and released.

      Brake Pedal Operation Stop Light Switch ST1
      Depressed ON ON
      Released OFF OFF

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

    5. Read the value displayed on the tester.

      OK
      Condition Specified Condition
      Brake pedal depressed STP signal ON
      Brake pedal released STP signal OFF
      Result
      Result Proceed to
      OK A
      NG (for Bulb Type Stop Light) B
      NG (for LED Type Stop Light) C

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    C

    CHECK HARNESS AND CONNECTOR (TERMINAL VOLTAGE) Click here

    B

  2. CHECK HARNESS AND CONNECTOR (TERMINAL VOLTAGE)


    1. A01VKHWE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A38-2 - Body ground Always 11 to 14 V
      A38-4 - Body ground Ignition switch ON 11 to 14 V

    OK

    INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  3. CHECK HARNESS AND CONNECTOR (TERMINAL VOLTAGE)


    1. A01VJOOE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A83-7 (B) - Body ground Always 11 to 14 V
      A83-6 (B) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  4. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly (for Bulb Type Stop Light) Click here.

    2. Inspect the stop light switch assembly (for LED Type Stop Light) Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  5. INSPECT ECM (STP AND ST1- VOLTAGE)


    1. A01VL4EE01
      Text in Illustration
      *a Brake pedal operation
      *b Brake Pedal Depressed
      *c Brake Pedal Released
      *d

      Front view of harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A59-28 (ST1-) - Body ground Released 11 to 14 V
      Depressed 0 to 3 V
      A59-29 (STP) - Body ground Released 0 to 3 V
      Depressed 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  6. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  7. REPLACE STOP LIGHT SWITCH ASSEMBLY


    1. Replace the stop light switch assembly Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR


    NEXT

  9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Clear the DTCs Click here.

    4. Turn the ignition switch to ON.

    5. Depress the brake pedal for 10 seconds or more.

    6. Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.

    7. Confirm that the pending DTC is not output again.


    NEXT

    END