C1439

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1439/66,C1445/66: Steering Angle Sensor Initialization Incomplete


DESCRIPTION

The skid control ECU acquires 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 the previous zero point.

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





INSPECTION PROCEDURE

NOTICE:
- When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.
- 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 voltage drops when the battery is removed, and confirm if this condition occurred.

HINT
- When DTC U0073/94, U0123/62, U0124/95, U0126/63, U0128/13, U0130/68 and/or U0131/67 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, U0126/63, U0128/13, U0130/68 and/or U0131/67 first U0073.
- 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

1. CHECK FOR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch OFF.

(c) Turn the power switch ON (IG) and check that no CAN communication system DTCs are output Reading and Clearing Diagnostic Trouble Codes.

(d) Drive the vehicle at a speed of 35 km/h (22 mph) and turn the steering wheel to the right and left and check that no speed sensor and yaw rate and deceleration sensor DTCs are output Reading and Clearing Diagnostic Trouble Codes.

Result





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 C1439/66 and/or C1445/66 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero calibration, such as when the power voltage drops.

D -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

C -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Electronically Controlled Brake System

B -- INSPECT CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK STEERING ANGLE SENSOR ZERO POINT CALIBRATION

(a) Drive the vehicle straight ahead at 35 km/h (22 mph) or more for at least 5 seconds.

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

HINT
If the 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.

NG -- ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the power switch OFF.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the power switch ON (READY).

(d) Drive the vehicle at a speed of 35 km/h (22 mph) or more and turn the steering wheel to the right and left.

(e) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result





HINT
If the same 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 calibration, such as when the power voltage drops.

B -- END

A -- REPLACE SKID CONTROL ECU Removal