Toyota Tundra. Manual — part 939

Fig. 72: Identifying Brake Pedal Load Sensing Switch Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK TERMINAL VOLTAGE (BOOSTER PEDAL MICRO SWITCH)

a. Disconnect A18 booster connector.

b. Turn the ignition switch to ON.

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

Standard Voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Fig. 73: Identifying A18 Active Brake Booster Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: Go to step 3

OK: Go To Next Step

NOTE:

When replacing the VSC actuator assembly, perform zero point calibration (See
CALIBRATION ).

Tester Connection

Condition

Specified Condition

A18-5 (STS) - Body ground

Always

Approximately 12 V

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

2. CHECK BOOSTER PEDAL MICRO SWITCH

a. When using an oscilloscope:

1. Connect the oscilloscope between terminals 1 (PSNO) and 5 (STS), 2 (PSNC) and 5 (STS) of

the brake booster with connector being connected.

2. Turn the ignition switch to ON.

3. Check the signal waveform while the brake pedal is depressed and released.

OK: Signal waveform changes as shown below.

Fig. 74: Checking Booster Pedal Micro Switch
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. When not using an oscilloscope:

1. Disconnect the A18 booster 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 SPECIFIED CONDITION TABLE

Tester Connection

Condition

Specified Condition

A18-2 (PSNC) - A18-5 (STS)

Brake pedal is depressed

6V

A18-1 (PSNO) - A18-5 (STS)

Brake pedal is released

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 75: Identifying A18 Active Brake Booster Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPLACE BRAKE BOOSTER ASSEMBLY

OK: Go To Next Step

3. CHECK HARNESS AND CONNECTOR (BOOSTER PEDAL MICRO SWITCH - SKID

CONTROL ECU)

a. Confirm that the skid control ECU connector and brake booster connector are properly connected.

b. Disconnect the A17 ECU connector.

c. Disconnect the A18 booster connector.

d. Inspect both the connector case and the terminal for deformation and corrosion.

OK: No deformation or corrosion.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection

Condition

Specified Condition

A17-24 (PSNC) - A18-2

(PSNC)

Always

Below 1 ohms

A17-24 (PSNC) - Body ground

Always

10 kohms or higher

A17-25 (PSNO) - A18-1

(PSNO)

Always

Below 1 ohms

A17-25 (PSNC) - Body ground

Always

10 kohms or higher

A17-27 (STS) - A18-5 (STS)

Always

Below 1 ohms

A17-27 (STS) - Body ground

Always

10 kohms or higher

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 76: Identifying A17 Skid Control ECU Connector And A18 Active Brake Booster
Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE VSC ACTUATOR ASSEMBLY (See REMOVAL )

DTC C1290/66: STEERING ANGLE SENSOR ZERO POINT MALFUNCTION

DESCRIPTION

DTC DETECTION CONDITION TABLE

WIRING DIAGRAM

Refer to WIRING DIAGRAM .

INSPECTION PROCEDURE

DTC Code

DTC Detection Condition

Trouble Area

C1290/66

Steering angle sensor zero point
deviates from zero point stored in
skid control ECU by 20 degrees
or more.



Steering angle sensor



Steering angle sensor circuit



CAN communication system

NOTE:

When replacing the VSC actuator assembly, perform zero point calibration (See

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra