SFI SYSTEM, Diagnostic DTC:P0504 and P1536

DTC Code DTC Name
P0504 Brake Switch "A" / "B" Correlation
P1536 Secondary Brake Information Sensor - Inconsistency in Deceleration or Invalid Signal

DESCRIPTION

The stop light switch assembly is installed to the brake pedal. The stop light switch assembly detects the operation of the brake pedal and sends a signal to the ECM.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0504

Brake Switch "A" / "B" Correlation

Stop light switch signals received by ECM via direct line communication and from skid control ECU via CAN communication do not match.

  • Stop light switch assembly

  • Wire harness or connector

  • ECM

Does not come on

DTC stored

P1536

Secondary Brake Information Sensor - Inconsistency in Deceleration or Invalid Signal

Stop light switch signals received by ECM via direct line communication and from skid control ECU via CAN communication do not match.

  • Stop light switch assembly

  • Wire harness or connector

  • ECM

Does not come on

DTC stored

MONITOR DESCRIPTION

These DTCs are stored when a malfunction is detected in the stop light switch signal. If the stop light switch signals received from the stop light switch assembly via direct line and the skid control ECU via CAN communication do not match, the ECM will store a DTC.

WIRING DIAGRAM

A327737E01

PROCEDURE

  1. INSPECT STOP LIGHT SWITCH ASSEMBLY

    1. Inspect the stop light switch assembly.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY

    Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)

    1. Disconnect the stop light switch assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A20-3 - A35-22 (BRK)

      Always

      Below 1 Ω

      A20-3 or A35-22 (BRK) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)

    A148738C19

    *a

    Front view of wire harness connector

    (to Stop Light Switch Assembly)

    1. Disconnect the stop light switch assembly 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

      A20-4 - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Result

    Proceed to

    OK

    A

    NG (w/ Entry and Start System)

    B

    NG (w/o Entry and Start System)

    C
    A

    REPLACE ECM

    Click here

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY)

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IGNITION SWITCH ASSEMBLY)