Dtc P0571 Stop Light Switch Circuit Malfunction

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
Cruise Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

CHECK HARNESS AND CONNECTOR (BATTERY - STOP LIGHT SWITCH)

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)

DTC P0571 Stop Light Switch Circuit Malfunction


DESCRIPTION

When the brake pedal is depressed, the stop light switch sends a signal to the ECM. Upon receiving the signal, the ECM cancels cruise control. Even if there is a malfunction in the stop light signal circuit while cruise control is in operation, normal driving is maintained due to a fail-safe function. When the brake pedal is depressed, positive voltage is applied to terminal STP of the ECM through the STOP fuse and stop light switch, and the ECM cancels cruise control.

DTC Code
DTC Detection Condition
Trouble Area
P0571
The voltages of terminals ST1- and STP of the ECM are both below 1 V for 0.5 seconds or more.
  1. Stop light switch circuit
  2. Stop light switch assembly
  3. ECM

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Cruise Control.Cruise Control System. Dtc P0571 Stop Light Switch Circuit Malfunction


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH)

  1. Using the intelligent tester, read the Data List (HILUX_TGN26 RM000000PM306GX.html).

    Cruise Control
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Stop Light SW M-CPU
    		Stop light switch signal (Main CPU) / ON or OFF
    		ON: Brake pedal depressed
    OFF: Brake pedal released
    		-
    OK:
    The display is as specified in the normal condition column.


NG
Go to step 2
OK

REPLACE ECM (HILUX_TGN26 RM0000013Z0019X.html)

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

  1. Disconnect the A24 stop light switch connector.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A24-2 - Body ground
    		Always
    		11 to 14 V
    A24-3 - Body ground
    		Ignition switch ON
    		11 to 14 V
    Ignition switch off
    		Below 1 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT STOP LIGHT SWITCH ASSEMBLY


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Cruise Control.Cruise Control System. Dtc P0571 Stop Light Switch Circuit Malfunction

  1. Remove the stop light switch (HILUX_TGN26 RM0000018VF00UX.html).

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 - 2
    		Pin pushed
    		10 kΩ or higher
    Pin not pushed
    		Below 1 Ω
    3 - 4
    		Pin pushed
    		Below 1 Ω
    Pin not pushed
    		10 kΩ or higher
    Text in Illustration
    *1
    		Pin
    *a
    		Not pushed
    *b
    		Pushed


NG
REPLACE STOP LIGHT SWITCH ASSEMBLY (HILUX_TGN26 RM0000018VF00UX.html)
OK


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

  1. Disconnect the A24 stop light switch connector.

  1. Disconnect the G38 ECM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A24-1 - G38-15 (STP)
    		Always
    		Below 1 Ω
    A24-4 - G38-14 (ST1-)
    A24-1 - Body ground
    		Always
    		10 kΩ or higher
    A24-4 - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (HILUX_TGN26 RM0000013Z0019X.html)