Toyota Tundra. Manual — part 937

Fig. 65: Identifying STOP Fuse From Engine Room Relay Block
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

OK: Go To Next Step

4. INSPECT STOP LIGHT CONTROL RELAY (BRK NO. 1, BRK NO. 2)

a. Remove the stop light control relays (BRK NO. 1 and BRK NO. 2) from the engine room relay

block.

Fig. 66: Identifying Stop Light Control Relay
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard Resistance: for BRK NO. 1

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection

Switch Condition

Specified Condition

3-4

When battery voltage is not

Below 1 ohms

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

for BRK NO. 2

TESTER CONNECTION SPECIFIED CONDITION TABLE

NG: REPLACE STOP LIGHT CONTROL RELAY

OK: Go To Next Step

5. INSPECT STOP LIGHT SWITCH ASSEMBLY

a. Disconnect the A4 switch connector.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

applied to terminals 1 and 2

3-5

When battery voltage is not
applied to terminals 1 and 2

10 kohms or higher

3-4

When battery voltage is applied
to terminals 1 and 2

10 kohms or higher

3-5

When battery voltage is applied
to terminals 1 and 2

Below 1 ohms

Tester Connection

Switch Condition

Specified Condition

3-4

When battery voltage is not
applied to terminals 1 and 2

Below 1 ohms

When battery voltage is applied
to terminals 1 and 2

10 kohms or higher

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

Pin pushed

Below 1 ohms

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 67: Identifying Stop Light Switch Assembly
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPLACE STOP LIGHT SWITCH ASSEMBLY (See REMOVAL )

OK: Go To Next Step

6. CHECK HARNESS AND CONNECTOR (BATTERY - SKID CONTROL ECU)

a. Disconnect the A17 ECU connector.

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

Standard Voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection

Switch Condition

Specified Condition

A17-11 (STP2) - Body ground

Brake pedal depressed

8 to 14 V

A17-11 (STP2) - Body ground

Brake pedal released

Below 4.0 V

A17-41 (STP) - Body ground

Brake pedal depressed

8 to 14 V

A17-41 (STP) - Body ground

Brake pedal released

Below 4.0 V

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 68: Identifying A17 Skid Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE VSC ACTUATOR ASSEMBLY (See REMOVAL )

DTC C1251/51, C0273/13: OPEN IN PUMP MOTOR CIRCUIT; OPEN IN ABS MOTOR RELAY
CIRCUIT

DESCRIPTION

The ABS motor relay (skid control ECU interior circuit) supplies the power to the ABS pump motor. While the
ABS is activated, the ECU turns the motor relay ON and operates the ABS pump motor.

DTC DETECTION CONDITION TABLE

DTC Code

DTC Detection Condition

Trouble Area

C1251/51

When any of following conditions
detected with normal battery
voltage (10 V or more):

1. Open in pump motor power

supply circuit or open in
motor power supply circuit
ground

2. Motor stuck mechanically

and does not operate

3. Motor coil shorted and

overcurrent flows



ABS1 H-fuse



VSC actuator assembly
(skid control ECU)

When one of following conditions
is met:

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra