Toyota Tundra. Manual — part 1579

The normal conditions are as shown in the table below. The signals can be read using the Techstream.

BRAKE PEDAL REFERENCE

DTC DETECTION CONDITION AND TROUBLE AREA REFERENCE CHART

WIRING DIAGRAM

Fig. 188: Brake Switch - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:



Read freeze frame data using the Techstream. 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, if the air-fuel ratio was lean or rich, and other
data from the time the malfunction occurred.



STP signal conditions can be checked using the Techstream.

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

Signal

Brake Pedal Released

In Transition

Brake Pedal Depressed

STP

OFF

ON

ON

ST1-

ON

ON

OFF

DTC

DTC Detection Condition

Trouble Area

P0504

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

a. Ignition switch ON

b. Brake pedal released

c. STP signal OFF when ST1-

signal OFF



Short in stop light switch
signal circuit



STOP fuse



IGN fuse



Stop light switch



ECM

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

d. Enter the following menus: Powertrain/Engine and ECT/All Data/Stop Light Switch.

e. Check the STP signal when the brake pedal is depressed and released.

STP SIGNAL CONDITIONS

1. CHECK STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)

a. Disconnect the A4 stop light switch connector.

Fig. 189: Identifying A4 Stop Light Switch Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard voltage

VOLTAGE SPECIFIED CONDITION

NG: Go to step 4

Brake Pedal Operation Specified Condition

Depressed

STP signal ON

Released

STP signal OFF

Tester Connection Switch Condition Specified Condition

A4-2 - Body ground

Always

11 to 14 V

A4-3 - Body ground Ignition switch ON

11 to 14 V

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

OK: Go to Next Step

2. INSPECT STOP LIGHT SWITCH ASSEMBLY

a. Remove the stop light switch (see REMOVAL ).

Fig. 190: Inspecting Stop Light Switch Assembly
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

RESISTANCE SPECIFIED CONDITIONS

NG: REPLACE STOP LIGHT SWITCH ASSEMBLY (See REMOVAL )

OK: Go to Next Step

3. CHECK ECM (STP AND ST1 - VOLTAGE)

a. Disconnect the A24 ECM connector.

b. Turn the ignition switch to ON.

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

Standard voltage

VOLTAGE SPECIFIED CONDITION

Tester Connection Switch Condition Specified Condition

1 - 2

Pin not pushed

Below 1 ohms

Pin pushed

10 kohms or higher

3 - 4

Pin not pushed

10 kohms or higher

Pin pushed

Below 1 ohms

Tester Connection

Condition

Specified Condition

A24-35 (ST1-) -

Body ground Brake pedal released

11 to 14 V

Brake pedal depressed

0 to 3 V

A24-36 (STP) - Body ground

Brake pedal released

0 to 3 V

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Fig. 191: Checking ECM Voltage
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE ECM (See REMOVAL )

4. INSPECT FUSE (STOP AND IGN)

a. Remove the STOP and IGN fuses from the engine room relay block.

Fig. 192: Identifying STOP And IGN Fuse On Engine Room Relay Block
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

RESISTANCE SPECIFIED CONDITIONS

NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED
TO FUSE AND REPLACE FUSE

Brake pedal depressed

11 to 14 V

Tester Connection Condition Specified Condition

STOP fuse

Always

Below 1 ohms

IGN fuse

Always

Below 1 ohms

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra