Toyota Tundra. Manual — part 917

VSC and/or TRAC does not
operate

SENSOR SIGNAL; LEFT REAR

WHEEL SPEED SENSOR

SIGNAL; LOW OUTPUT

SIGNAL OF REAR SPEED

SENSOR RH (TEST MODE

DTC); LOW OUTPUT SIGNAL

OF REAR SPEED SENSOR LH

(TEST MODE DTC);

ABNORMAL CHANGE IN

OUTPUT SIGNAL OF REAR

SPEED SENSOR RH (TEST
MODE DTC); ABNORMAL

CHANGE IN OUTPUT SIGNAL

OF REAR SPEED SENSOR LH

(TEST MODE DTC); OPEN

CIRCUIT IN RIGHT REAR

WHEEL SPEED SENSOR

CIRCUIT; OPEN CIRCUIT IN

LEFT REAR WHEEL SPEED

SENSOR CIRCUIT

Yaw rate and deceleration sensor

circuit

DTC C0371/71, C1234/34,

C1244/44, C1279/79: YAW RATE

SENSOR (TEST MODE DTC);

STUCK IN DECELERATION

SENSOR; YAW RATE SENSOR

MALFUNCTION; OPEN OR

SHORT IN DECELERATION

SENSOR CIRCUIT;

DECELERATION SENSOR

OUTPUT VOLTAGE

MALFUNCTION (TEST MODE

DTC)

Steering angle sensor circuit

DTC C1231/31: STEERING

ANGLE SENSOR CIRCUIT

MALFUNCTION

If symptoms still occur even after

above circuits in suspected areas

inspected and proved to be

normal, replace VSC actuator

(skid control ECU)

BRAKE ACTUATOR

Sensor signal check cannot be
performed

TS and CG terminal circuit

TS AND CG TERMINAL

CIRCUIT

VSC actuator (skid control ECU)

BRAKE ACTUATOR

Check for DTCs again and make

sure that normal system code

displayed

DTC CHECK/CLEAR

TC and CG terminal circuit

TC AND CG TERMINAL

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

TERMINALS OF ECU

1. SKID CONTROL ECU

DTC check cannot be performed

CIRCUIT

If symptoms still occur even after

above circuits in suspected areas

inspected and proved to be

normal, replace VSC actuator

(skid control ECU)

BRAKE ACTUATOR

ABS warning light abnormal
(Remains on)

ABS warning light circuit

ABS WARNING LIGHT

REMAINS ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

ABS warning light abnormal
(Does not come on)

ABS warning light circuit

ABS WARNING LIGHT DOES

NOT COME ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

BRAKE warning light abnormal
(Remains on)

BRAKE warning light circuit

BRAKE WARNING LIGHT

REMAINS ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

BRAKE warning light abnormal
(Does not come on)

BRAKE Warning light circuit

BRAKE WARNING LIGHT

DOES NOT COME ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

SLIP indicator light abnormal
(Remains on)

SLIP indicator light circuit

SLIP INDICATOR LIGHT

REMAINS ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

SLIP indicator light abnormal
(Does not come on)

SLIP indicator light circuit

SLIP INDICATOR LIGHT

DOES NOT COME ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

VSC OFF indicator light
abnormal (Remains on)

VSC OFF indicator light circuit

VSC OFF INDICATOR LIGHT

REMAINS ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

VSC OFF indicator light
abnormal (Does not come on)

VSC OFF indicator light circuit

VSC OFF INDICATOR LIGHT

DOES NOT COME ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

AUTO LSD indicator light
abnormal (Remains on)

AUTO LSD indicator light circuit

AUTO LSD INDICATOR

LIGHT REMAINS ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

AUTO LSD indicator light
abnormal (Does not come on)

AUTO LSD indicator light circuit

AUTO LSD INDICATOR

LIGHT DOES NOT COME ON

VSC actuator (skid control ECU)

BRAKE ACTUATOR

Skid control buzzer abnormal

Skid control buzzer circuit

SKID CONTROL BUZZER

CIRCUIT

VSC actuator (skid control ECU)

BRAKE ACTUATOR

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

CONNECTOR TERMINAL REFERENCE TABLE

Terminal No. (Symbols)

Terminal Description

A17-1 (GND1)

Skid control ECU ground

A17-2 (STPO)

Stop light control relay (BRK NO. 1) signal input

A17-3 (PKB2)

Parking brake switch signal input

A17-4 (CANL)

Vehicle CAN communication line

A17-5 (CANH)

Vehicle CAN communication line

A17-6 (EXI2)

A.D.D. detection switch signal input (4WD)

A17-7 (D/G)

Diagnosis tester communication line

A17-8 (BZ)

Buzzer drive input

A17-9 (IG1)

IG1 power supply

A17-10 (TS)

Sensor check input

A17-11 (STP2)

Stop light switch and stop light control relay (BRK NO. 1) signal input

A17-12

No pin

A17-13 (CSW)

VSC OFF switch signal input

A17-14 (SP1)

Vehicle speed pulse signal output

A17-15

No pin

A17-16 (+BM)

Motor relay power supply

A17-17 (BST)

Brake booster solenoid ground

A17-18 (PIM)

Pedal stroke sensor (Delta S sensor) input line

A17-19 (GYAW)

Yaw rate sensor ground

A17-20

No pin

A17-21 (E3)

Pedal stroke sensor (Delta S sensor) ground

A17-22 (VCP)

Pedal stroke sensor (Delta S sensor) power source

A17-23

No pin

A17-24 (PSNC)

Brake booster micro switch (Normal Close) signal input

A17-25 (PSNO)

Brake booster micro switch (Normal Open) signal input

A17-26 (VYS)

Yaw rate sensor power source

A17-27 (STS)

Brake booster micro switch power source

A17-28

No pin

A17-29 (SS2)

Yaw rate sensor signal line (CANL)

A17-30 (SS1)

Yaw rate sensor signal line (CANH)

A17-31 (BSTP)

Brake booster solenoid power source

A17-32

No pin

A17-33 (FL-)

Front wheel LH speed signal line

A17-34 (FL+)

Front wheel LH speed signal line

A17-35 (BSW)

Stop light control relay (BRK NO. 2) drive input

A17-36 (RR+)

Rear wheel RH speed signal line

A17-37 (RR-)

Rear wheel RH speed signal line

A17-38

No pin

A17-39

No pin

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 26: Identifying A17 Skid Control ECU Connector Terminal
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2. CHECK SKID CONTROL ECU

a. Disconnect the A17 ECU connector.

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

HINT:

Voltage cannot be measured with the connector connected to the skid control ECU as the connector
is watertight.

CONNECTOR TERMINAL REFERENCE TABLE

A17-40

No pin

A17-41 (STP)

Stop light switch signal input

A17-42 (RL-)

Rear wheel LH speed signal line

A17-43 (RL+)

Rear wheel LH speed signal line

A17-44

No pin

A17-45 (FR+)

Front wheel RH speed signal line

A17-46 (FR-)

Front wheel RH speed signal line

A17-47 (+BS)

Solenoid relay power supply

Terminal No.

(Symbols)

Wiring Color

Terminal

Description

Condition

Specified

Condition

A17-1 (GND1) -

Body ground

W-B - Body

ground

Skid control ECU

ground

Always

Below 1 ohms

A17-2 (STP0) -

Body ground

BR - Body

ground

Stop light control

relay (BRK NO. 1)

signal input

Ignition switch

ON

11 to 14 V

A17-3 (PKB2) -

Body ground

LG - Body

ground

Parking brake switch

signal input

Parking brake

switch ON

Below 1 ohms

A17-6 (EXI2) -

Body ground

GR - Body

ground

A.D.D. detection

switch signal input

(4WD)

A.D.D. detection

switch ON

Below 1 ohms

A17, 7 (D/G)-DLC

Terminal

-

Diagnosis tester

communication line

Always

Below 1 ohms

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra