Toyota Tundra. Manual — part 933

C: REPLACE ECM (See REMOVAL )

D: REPLACE ECM (See REMOVAL )

A: REPAIR OR REPLACE HARNESS OR CONNECTOR

DTC C1231/31: STEERING ANGLE SENSOR CIRCUIT MALFUNCTION

DESCRIPTION

The steering angle sensor signal is sent to the skid control ECU via the CAN communication system. When
there is a malfunction in the CAN communication system, it will be detected by the diagnostic function.

DTC DETECTION CONDITION TABLE

HINT:

DTC C1231/31 is erased automatically when the ignition switch is turned from OFF to ON after the voltage
supply to the steering angle sensor returns to normal.

WIRING DIAGRAM

DTC Code

DTC Detection Condition

Trouble Area

C1231/31

When any of following conditions
detected:

1. Skid control ECU receives

abnormal signals from
steering angle sensor.

2. Skid control ECU receives

abnormal voltage signals
from steering angle sensor.

3. Despite calibration being

conducted by skid control
ECU, it does not finish
within 15 seconds.

4. Abnormal difference

between yaw rate and
deceleration sensor and
steering angle sensor signals
continues for approximately
2 seconds or more during
driving.



Steering angle sensor



Steering angle sensor circuit



Steering angle sensor power
supply



CAN communication system

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

Fig. 56: Identifying Steering Angle Sensor Circuit Malfunction Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:

When U0073/94, U0123/62, U0124/69 or U0126/63 is output together with C1231/31, inspect and repair the
trouble areas indicated by U0073/94, U0123/62, U0124/69 or U0126/63 first.

1. PERFORM INITIALIZATION OF STEERING ANGLE SENSOR

a. Check that the steering wheel is in the centered position.

b. Disconnect the negative battery terminal for more than 2 seconds.

NOTE:

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

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

c. Reconnect the negative battery terminal.

d. After driving the vehicle straight ahead at 15 km/h (9.3 mph) or more for a few seconds, drive the

vehicle at a speed of 45 km/h (28 mph) or more and turn the steering wheel to the right and left for
several seconds.

2. READ VALUE USING TECHSTREAM (STEERING ANGLE SENSOR)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream on.

d. Check that the steering wheel is centered.

e. Select the Data List mode on the Techstream.

ABS/VSC/TRAC

DIAGNOSTIC NOTE TABLE

f. Check that the steering wheel turning angle of the steering angle sensor changes when turning the

steering wheel.

OK: Turning the steering wheel to the left: Value increases

Turning the steering wheel to the right: Value decreases

NG: Go to step 4

OK: Go To Next Step

3. RECONFIRM DTC

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

b. Start the engine.

c. After driving the vehicle straight ahead at 15 km/h (9.3 mph) or more for a few seconds, drive the

NOTE:

After the ignition switch is turned OFF, the navigation system
requires approximately 90 seconds to record various types of
memory and settings. As a result, after turning the ignition switch
OFF, wait 90 seconds or more before disconnecting the cable from
the negative (-) battery terminal.

Tester Display

Measurement

Item/Range

Normal Condition

Diagnostic Note

Steering Angle Sensor

Steering angle sensor /
min.: -3276.8°, max.:
3276.7°

Left turn: Increase
Right turn: Decrease

-

Steering Angle Value

Steering angle value /
min.: -3276.8°, max.:
3276.7°

Min.: -3276.8°
Max.: 3276.7°

-

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra

vehicle at a speed of 45 km/h (28 mph) or more and turn the steering wheel to the right and left for
several seconds.

d. Check if the same DTC is recorded (See DTC CHECK/CLEAR ).

Result

RESULT TABLE

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

A: REPLACE VSC ACTUATOR ASSEMBLY (See REMOVAL )

4. CHECK CAN COMMUNICATION SYSTEM

a. Check if a CAN communication system DTC is output (See DIAGNOSIS SYSTEM ).

Result

RESULT TABLE

B: GO TO CAN COMMUNICATION SYSTEM (See HOW TO PROCEED WITH
TROUBLESHOOTING )

A: Go To Next Step

5. CHECK STEERING ANGLE SENSOR

a. Check that the steering angle sensor has been installed correctly (See INSPECTION ).

OK: The sensor is installed correctly.

NG: INSTALL STEERING ANGLE SENSOR CORRECTLY

OK: Go To Next Step

6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STEERING ANGLE

SENSOR)

a. Remove the steering wheel and the column cover lower.

b. Disconnect the steering angle sensor connector.

Result

Proceed to

DTC is output

A

DTC is not output

B

Result

Proceed to

DTC is not output

A

DTC is output

B

2009 Toyota Tundra

2009 BRAKES Brake Control - Tundra