СИСТЕМА ECD, Diagnostic DTC:P1520

DTC Code DTC Name
P1520 Stop Light Switch Circuit Malfunction

DESCRIPTION

In this system, the signal of the stop light switch is used to judge whether the stop light system is abnormal or not.

The stop light switch has a duplex system (signals STP and ST1-) to recognize the abnormality when the signals of depressing and releasing the brake pedal are detected simultaneously.

Tech Tips

The normal condition is shown in the table below.

Signal Brake Pedal Released In Transition Brake Pedal Depressed
STP Off On On
ST1- On On Off
DTC No. DTC Detection Condition Trouble Area
P1520

Conditions (a), (b) and (c) continue for 0.5 seconds or more(1 trip detection logic):

(a) Ignition switch is ON.

(b) Brake pedal is released.

(c) STP signal is off when ST1- signal is off.

  • Open or short in stop light switch signal circuit

  • Stop light switch

  • ECM

WIRING DIAGRAM

A01XJ6VE03
*a from IG2 Relay
*b from Battery
*c STOP
*d Stop Light Switch

CAUTION / NOTICE / HINT

Note

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

Tech Tips

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.

PROCEDURE


  1. CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)


    1. B001I2QE01
      *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
      A85-1 (B) - Body ground Always 11 to 14 V
      A85-5 (B) - Body ground Ignition switch ON 11 to 14 V

    3. Reconnect the stop light switch assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - INTEGRATION RELAY, BATTERY)

    OK

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


    1. Disconnect the stop light switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A85-3 (GND) - Body ground Always Below 1 Ω

    3. Reconnect the stop light switch assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ECM (STP, ST1- VOLTAGE)


    1. A01XKH3E01
      Text in Illustration
      *a Brake pedal depressed
      *b Brake pedal released
      *c

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Brake Pedal Condition Specified Condition
      G182-9 (STP) - C161-5 (E1) Depressed 11 to 14 V
      Released Below 1.5 V
      G182-10 (ST1-) - C161-5 (E1) Depressed Below 1.5 V
      Released 11 to 14 V

    OK

    REPLACE ECM Click here

    NG

  4. CHECK HARNESS AND CONNECTOR


    1. Disconnect the stop light switch assembly connector.

    2. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A85-2 - G182-9 (STP) Always Below 1 Ω
      A85-4 - G182-10 (ST1-) Always Below 1 Ω
      A85-2 or G182-9 (STP) - Body ground Always 10 kΩ or higher
      A85-4 or G182-10 (ST1-) - Body ground Always 10 kΩ or higher

    4. Reconnect the stop light switch assembly connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR