Last Modified: 11-29-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: Sequoia Doc ID: RM000000W88073X
Title: 2UZ-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

P0724

Brake Switch "B" Circuit High

DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling while driving in the lock-up condition when the brakes are suddenly applied.

When the brake pedal is depressed, this switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

DTC No.

DTC Detection Condition

Trouble Area

P0724

Stop light switch remains ON even when vehicle is driven in GO (30 km/h (18.65 mph) or more) and STOP (less than 3 km/h (1.86 mph)) pattern 5 times (2 trip detection logic)
  • Short in stop light switch signal circuit
  • Stop light switch
  • ECM

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains ON. When the stop light switch remains ON during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC. The vehicle must GO (30 km/h (18.65 mph) or more) and STOP (less than 3 km/h (1.86 mph)) 5 times for 2 driving cycles in order for the DTC to be output.

MONITOR STRATEGY

Related DTCs

P0724: Stop light switch/Range check/Rationality

Required sensors/Components

Stop light switch, Vehicle speed sensor

Frequency of operation

Continuous

Duration

GO and STOP 5 times

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever this DTC is not present.

None

Battery voltage

8 V or more

Starter

OFF

Ignition switch

ON

GO (Vehicle speed is 30 km/h (18.65 mph) or more)

Once

STOP (Vehicle speed is less than 3 km/h (1.86 mph))

Once

TYPICAL MALFUNCTION THRESHOLDS

Brake switch

Stuck ON

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Using the Techstream to perform the Data List allows switch, sensor, actuator and other item values to be read without removing any parts. Reading the Data List early in troubleshooting is one way to save time.

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

  • Warm up the engine.
  • Turn the ignition switch off.
  • Connect the Techstream to the DLC3.
  • Turn the ignition switch to ON.
  • Turn the Techstream ON.
  • Enter the following menus: Powertrain / Engine / Data List /
  • Follow the instructions on the Techstream and read the Data List.

Item

Measurement Item/

Range (Display)

Normal Condition

Diagnostic Note

Stop Light Switch

Stop light switch status/

ON or OFF
  • Brake pedal is depressed: ON
  • Brake pedal is released: OFF

-

PROCEDURE

1.

INSPECT STOP LIGHT SWITCH


(a) Remove the stop light switch.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

1 - 2

Switch pin not pushed

Below 1 Ω

Switch pin pushed

10 kΩ or higher

3 - 4

Switch pin not pushed

10 kΩ or higher

Switch pin pushed

Below 1 Ω
OK

2.

CHECK HARNESS AND CONNECTOR (ECM - BATTERY)

(a) Disconnect the ECM connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A27-26 (STP) - Body ground

Brake pedal is depressed

11 to 14 V

A27-26 (STP) - Body ground

Brake pedal is released

Below 1 V
OK