Toyota Venza: Steering Angle Sensor Initialization Incomplete (C1439/31,C1445/31)

Toyota Venza Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / Steering Angle Sensor Initialization Incomplete (C1439/31,C1445/31)

DESCRIPTION

The skid control ECU acquires the steering angle sensor zero point every time the ignition switch is turned to ON and the vehicle is driven at 50 km/h (31 mph) or more for approximately 30 seconds. The ECU also stores previous zero points.

Warning of the steering angle sensor zero point malfunction will be cancelled by turning the ignition switch off.

DTC Code	DTC Detection Condition	Trouble Area
C1439/31	After the steering angle sensor zero point calibration is cleared due to, for example, fluctuations in the power source, the steering angle sensor zero point calibration cannot be obtained for 120 seconds of continuous driving.	Steering angle sensor Yaw rate and acceleration sensor Brake actuator assembly (Skid control ECU)
C1445/31	Steering angle sensor zero point calibration cannot be obtained when the vehicle is driven without a record of steering angle sensor zero point calibration at a speed of 50 km/h (31 mph) or more for 120 seconds or more without the brake pedal being depressed.	Steering angle sensor Yaw rate and acceleration sensor Brake actuator assembly (Skid control ECU)

CAUTION / NOTICE / HINT

NOTICE:

Before proceeding with the inspection, explain to the customer that the output DTC is related to temporary loss of the steering angle zero point calibration, such as when the power source voltage drops when the battery is removed, and confirm that this condition occurred.

HINT:

When U0073/94, U0123/62, U0124/95 and/or U0126/63 is output together with C1439/31 and/or C1445/31, inspect and repair the trouble areas indicated by U0073/94, U0123/62, U0124/95 and/or U0126/63 first (See page ).

When the speed sensor or the yaw rate and acceleration sensor has trouble, DTCs for the steering angle sensor may be output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate and acceleration sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed sensor and yaw rate and acceleration sensor first, and then inspect and repair the steering angle sensor.

PROCEDURE

CHECK DTC

(a) Clear the DTCs (See page ).

(b) Turn the ignition switch off.

(d) Drive the vehicle and turn the steering wheel to the right and left at a speed of 50 km/h (31 mph) and check that no speed sensor and yaw rate and acceleration sensor DTCs are output (See page ).

Result	Proceed to
DTCs (C1439/31 and/or C1445/31) are output	A
CAN communication system DTC is output	B
Speed sensor and/or yaw rate and acceleration sensor DTC is output	C
DTCs (C1439/31 and C1445/31) are not output	D

HINT:

If there is a malfunction in the speed sensor or the yaw rate and acceleration sensor, an abnormal value may be output although the steering angle sensor is normal.
If the speed sensor and the yaw rate and acceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor.
If the same DTC C1439/31 and/or C1445/31 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero point calibration, such as when the power source voltage drops.

INSPECT CAN COMMUNICATION SYSTEM

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

CHECK FOR INTERMITTENT PROBLEMS

2.	CHECK STEERING ANGLE SENSOR ZERO POINT CALIBRATION

(a) Drive the vehicle straight ahead at 50 km/h (31 mph) or more for at least 30 seconds.

(b) Check that the centered position of the steering wheel is correctly set while driving straight ahead.

HINT:

If front wheel alignment and steering position are adjusted as a result of an off-centered position of the steering wheel, acquire yaw rate and acceleration sensor zero point again after the adjustments are completed.

OK:

The centered position of the steering wheel is correctly set.

ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION

3.	REPLACE SPIRAL CABLE SUB-ASSEMBLY (STEERING ANGLE SENSOR)

(a) Turn the ignition switch off.

(b) Replace the spiral cable sub-assembly (steering angle sensor) (See page ).

4.	RECONFIRM DTC

(a) Clear the DTCs (See page ).

(b) Start the engine.

(c) Drive the vehicle and turn the steering wheel to the right and left at the speed of 50 km/h (31 mph) or more for at least 120 seconds.

(d) Check if the same DTC is recorded (See page ).

Result	Proceed to
DTCs (C1439/31 and/or C1445/31) are output	A
DTCs (C1439/31 and C1445/31) are not output	B

HINT:

If the same DTC C1439/31 and/or C1445/31 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero point calibration, such as when the power source voltage drops.

REPLACE BRAKE ACTUATOR ASSEMBLY

END

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