ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1439/66 and C1445/66

DTC Code	DTC Name
C1439/66	Steering Angle Sensor Initialization Incomplete
C1445/66	Vehicle Driven with Steering Angle Sensor not Initialized

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) acquires the steering angle sensor zero point every time the power switch is turned on (IG) and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores previous zero points.

DTCs C1439/66 and C1445/66 will be cleared when the power switch is turned off.


DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1439/66	Steering Angle Sensor Initialization Incomplete	752	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 0.048 seconds of continuous driving.	Steering angle sensor (Spiral with sensor cable sub-assembly) Yaw rate and acceleration sensor (Airbag ECU assembly) Skid control ECU (Brake booster with master cylinder assembly)	VSC DTC
C1445/66	Vehicle Driven with Steering Angle Sensor not Initialized	753	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 35 km/h (22 mph) or more for 60 seconds or more.	Steering angle sensor (Spiral with sensor cable sub-assembly) Yaw rate and acceleration sensor (Airbag ECU assembly) Skid control ECU (Brake booster with master cylinder assembly)	VSC DTC

CAUTION / NOTICE / HINT

Note:

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 auxiliary battery is removed. Confirm whether this condition occurred.

Tip:

When DTC U0073/94, U0123/62, U0124/95 and/or U0126/63 is output together with DTC C1439/66 and/or C1445/66, inspect and repair the trouble areas indicated by DTC U0073/94, U0123/62, U0124/95 and/or U0126/63 first.
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When a speed sensor or the yaw rate and acceleration sensor (airbag ECU assembly) is malfunctioning, DTCs for the steering angle sensor (spiral with sensor cable sub-assembly) may be output even when the steering angle sensor (spiral with sensor cable sub-assembly) is normal. When DTCs for a speed sensor or the yaw rate and acceleration sensor (airbag ECU assembly) are output together with other DTCs for the steering angle sensor (spiral with sensor cable sub-assembly), inspect and repair the speed sensor and yaw rate and acceleration sensor (airbag ECU assembly) first, and then inspect and repair the steering angle sensor (spiral with sensor cable sub-assembly).

PROCEDURE

CHECK DTC

Clear the DTCs.
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Chassis > ABS/VSC/TRC > Clear DTCs
Turn the power switch off.
Turn the power switch on (IG) again and check that no CAN communication system DTCs are output.
for LHD:Click here Click here Click here
for RHD:Click here Click here Click here
Turn the power switch on (READY).

Drive the vehicle at a speed of 35 km/h (22 mph), turn the steering wheel to the right and left, and check that no speed sensor, yaw rate and acceleration sensor and steering angle sensor DTCs are output.

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Chassis > ABS/VSC/TRC > Trouble Codes

Result


Result	Proceed to
DTCs C1439/66 and/or C1445/66 are output.	A
CAN communication system DTCs are output.	B
Speed sensor, yaw rate and acceleration sensor and/or steering angle sensor DTCs are output.	C
DTCs C1439/66 and C1445/66 are not output.	D

Tip:

When CAN communication system DTCs are output, repair the CAN communication system before repairing each corresponding sensor.
If there is a malfunction in a speed sensor or the yaw rate and acceleration sensor (airbag ECU assembly), an abnormal value may be output although the steering angle sensor (spiral with sensor cable sub-assembly) is normal.
If speed sensor and yaw rate and acceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor (spiral with sensor cable sub-assembly).
If DTC C1439/66 and/or C1445/66 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.

B

INSPECT CAN COMMUNICATION SYSTEM

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for RHD:Click here

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 35 km/h (22 mph) or more for at least 5 seconds.
Check that the steering wheel is centered correctly while driving straight ahead.

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

OK

The steering wheel is centered correctly.

Result


Proceed to
OK
NG

NG

ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION

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OK

RECONFIRM DTC

Turn the power switch off.
Clear the DTCs.
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Chassis > ABS/VSC/TRC > Clear DTCs
Turn the power switch off.
Turn the power switch on (READY).
Drive the vehicle at a speed of 35 km/h (22 mph) or more 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 C1439/66 and C1445/66 are not output.	A
Yaw rate and acceleration sensor and/or steering angle sensor DTCs are output.	B

Tip:

If DTC C1439/66 and/or C1445/66 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.

A

END

B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

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