VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1439 and C1445

DTC Code	DTC Name
C1439	Steering Angle Sensor Initialization Incomplete
C1445	Vehicle Driven with Steering Angle Sensor not Initialized

DESCRIPTION

The skid control ECU (brake actuator assembly) 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.


DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
C1439	Steering Angle Sensor Initialization Incomplete	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 115 seconds of continuous driving.	Steering angle sensor (spiral cable sub-assembly) Yaw rate and acceleration sensor (airbag sensor assembly)	Tire pressure warning light (w/ tire pressure warning system) is off.
C1445	Vehicle Driven with Steering Angle Sensor not Initialized	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 15 km/h (9 mph) or more for 115 seconds or more without the brake pedal being depressed.	Steering angle sensor (spiral cable sub-assembly) Yaw rate and acceleration sensor (airbag sensor assembly)	Tire pressure warning light (w/ tire pressure warning system) is off.

CAUTION / NOTICE / HINT

Note:

Because this DTC is related to a temporary loss of steering angle zero point calibration, before proceeding with the inspection, it is useful to confirm whether the power source voltage was interrupted by an operation such as removal or disconnection of the battery.

Tip:

When DTC U0073, U0123 and/or U0126 is output together with DTC C1439 and/or C1445, inspect and repair the trouble areas indicated by DTC U0073, U0123 and/or U0126 first.
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When a speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly) is malfunctioning, DTCs for the steering angle sensor (spiral cable sub-assembly) may be stored even when the steering angle sensor (spiral cable sub-assembly) is normal. When DTCs for a speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) are output together with DTCs for the steering angle sensor (spiral cable sub-assembly), inspect and repair the speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) first, and then inspect and repair the steering angle sensor (spiral cable sub-assembly).

PROCEDURE

CHECK DTC

Clear the DTCs.
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Chassis > ABS/VSC/TRC > Clear DTCs
Turn the ignition switch off.
Turn the ignition switch to ON again and check that no CAN communication system DTCs are output.
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Drive the vehicle at a speed of 50 km/h (31 mph) and turn the steering wheel to the right and left and check that no speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output.

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Chassis > ABS/VSC/TRC > Trouble Codes

Result


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

Tip:

If a speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly) is malfunctioning, DTCs for the steering angle sensor (spiral cable sub-assembly) may be stored even though the steering angle sensor (spiral cable sub-assembly) is normal.
If speed sensor and yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output simultaneously, repair these malfunctions and then inspect the steering angle sensor (spiral cable sub-assembly).
If DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of steering angle zero point calibration, such as a loss of calibration due to the power source voltage being low.

B

INSPECT CAN COMMUNICATION SYSTEM

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C

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

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D

USE SIMULATION METHOD TO CHECK

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A

CHECK STEERING ANGLE SENSOR ZERO POINT CALIBRATION

Drive the vehicle straight ahead at 50 km/h (31 mph) or more for at least 30 seconds.
Check that the steering wheel is correctly centered while driving straight ahead.

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

OK

The steering wheel is correctly centered.

Result


Proceed to
OK
NG

NG

ADJUST FRONT WHEEL ALIGNMENT OR STEERING

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OK

REPLACE SPIRAL CABLE SUB-ASSEMBLY

Turn the ignition switch off.
Replace the steering angle sensor (spiral cable sub-assembly).
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Result


Proceed to
NEXT

Clear the DTCs.
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Chassis > ABS/VSC/TRC > Clear DTCs
Turn the ignition switch off.
Start the engine.
Drive the vehicle at a speed of 50 km/h (31 mph) or more for at least 120 seconds and turn the steering wheel to the right and left.

Check if the same DTC is output.

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Chassis > ABS/VSC/TRC > Trouble Codes

Result


Result	Proceed to
DTCs C1439 and C1445 are not output.	A
Yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output.	B

Tip:

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

A

END

B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

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