Toyota Tundra. Manual — part 943

Fig. 85: Identifying A17 Skid Control ECU And A25 4WD Control ECU Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go To Next Step

3. CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BODY GROUND)

a. Confirm that the 4WD control ECU connector and A.D.D. actuator connectors are properly

connected.

Fig. 86: Identifying A25 4WD Control ECU Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

b. Disconnect the A25 ECU connector.

c. Inspect the connector case and the terminal for deformation and corrosion.

OK: No deformation or corrosion.

d. Connect the A25 ECU connector.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go To Next Step

4. RECONFIRM DTC

a. Clear the DTC (s) (See DTC CHECK/CLEAR ).

b. Start the engine.

c. Check if the same DTC (s) is output (See DTC CHECK/CLEAR ).

Result

RESULT TABLE

B: USE SIMULATION METHOD TO CHECK (See HOW TO PROCEED WITH
TROUBLESHOOTING )

A: REPLACE 4WD CONTROL ECU (See REMOVAL )

DTC C1281/81, C1360/61 MASTER CYLINDER PRESSURE SENSOR OUTPUT MALFUNCTION
(TEST MODE DTC); MALFUNCTION IN COMPARATIVE MASTER CYLINDER PRESSURE
SENSOR

DESCRIPTION

The master cylinder pressure sensor is built into the VSC actuator.

Tester Connection

Condition

Specified Condition

A25-15 (ADD) - Body ground

4WD (A.D.D. detection switch

ON)

Below 1 ohms

2WD (A.D.D. detection switch

OFF)

10 kohms or higher

Result

Proceed to

DTC is output

A

DTC is not output

B

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

DTC DETECTION CONDITION TABLE

INSPECTION PROCEDURE

1. CHECK BRAKE PEDAL

a. Check if the brake pedal is spongy.

OK: The brake pedal is normal.

NG: BLEED AIR (See REPLACEMENT )

OK: Go To Next Step

2. PERFORM TEST MODE PROCEDURE (MASTER CYLINDER PRESSURE SENSOR)

a. Perform TEST MODE PROCEDURE .

b. Check if the test mode procedure (master cylinder pressure sensor) is finished successfully.

Result

RESULT TABLE

DTC Code

DTC Detection Condition

Trouble Area

C1360/61

When any of the following
conditions are detected:

1. When malfunction occurs

during pressure sensor initial
check.

2. When signal value is out of

range.

3. When zero point calibration

value is out of range.



Master cylinder pressure
sensor



Master cylinder pressure
sensor circuit

C1281/81

Detected only during test mode.



Master cylinder pressure
sensor



Master cylinder pressure
sensor circuit



Stop light switch circuit



Skid control ECU

NOTE:

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

Result

Proceed to

The test mode procedure (master cylinder
pressure sensor) is not finished successfully

A

The test mode procedure (master cylinder

B

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

B: REPLACE VSC ACTUATOR ASSEMBLY (See REMOVAL )

A: Go To Next Step

3. REPLACE BRAKE BOOSTER ASSEMBLY

a. Replace the brake booster (See REMOVAL ).

4. RECONFIRM DTC

a. Clear the DTC (See DTC CHECK/CLEAR ).

b. Turn the ignition switch off.

c. Turn the ignition switch to ON, and check if the same DTC is stored in the memory (See DTC

CHECK/CLEAR ).

Result:

RESULT TABLE

B: END

A: REPLACE VSC ACTUATOR ASSEMBLY (See REMOVAL )

DTC C1370/73: ENGINE OR TRANSMISSION SYSTEM MATCHING ERROR

DESCRIPTION

This DTC is set by the skid control ECU when the ECM is replaced with one that has different engine and
transmission information than the information stored in the skid control ECU.

This DTC is also set when the VSC actuator assembly (skid control ECU) is replaced with one that has different
engine and transmission information than the information stored in the ECM.

DTC DETECTION CONDITION TABLE

HINT:

pressure sensor) is finished successfully

Result

Proceed to

DTC is output

A

DTC is not output

B

DTC Code

DTC Detection Condition

Trouble Area

C1370/73

Information relating to engine,
transmission, drive source or
destination stored in ECM does
not match information stored in
skid control ECU.



VSC actuator assembly (skid
control ECU)



ECM

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra