Kia Sedona (2008 year). Instruction — part 17

The Steering Angle Sensor (SAS) is used to determine turning direction and speed of the steering wheel. The
HECU uses the signals from the SAS when performing ESC-related calculations.

DTC DESCRIPTION

If the SAS signal is different from calculated value by yaw-rate sensor and wheel speed sensor, mechanically
impossible SAS signal is detected, there is a difference between SAS signal and driving condition of the vehicle
calculated from yaw-rate sensor and lateral G sensor, a failure is detected.

DTC DETECTING CONDITION

DTC DETECTING CONDITION CHART

Item

Detecting Condition

Possible cause

DTC strategy



Voltage Monitoring

Case 1

Monitoring Period



Continuous

Enable Conditions



During normal driving conditions
the long time filtered driving
direction is straight ahead. The
long time filtered SAS-value is
equivalent to the offset. If the
offset value exceeds a threshold
of approximately 15 deg a SAS-
fault is determined. Failure
detection time depends on the
driving distance, vehicle speed
and on the amount of failed SAS
signal. Within 30 km of
symmetrical driving the
calculated offset corresponds to
the sensor offset.

Monitoring Period



Continuous (If the following
conditions are satisfied)

1. After SAS-initialization

and vehicle reference speed
> 1.4 m/s

2. No under voltage

3. At least one SAS-message

was sent in the current 20
ms-cycle.]



A SAS-gradient-failure is set, if

1. Signal gradient (steering

angle velocity) from one 20
ms-cycle to another is
higher than 40° or

2008 Kia Sedona

2008 BRAKES ABS (Anti-Lock Brake System) - Sedona

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Case 2

Enable Conditions

2. Change of this gradient

(steering angle
acceleration) is higher than
15°: | (LwInK0K1 .
LwInK1K2)| > 15° and |
(LwInK0K1 + LwInK1K2)|
> 15°



LwInK0K1:
Difference of the
SAS-signal between
the current 20 ms-
cycle and the last 20
ms-cycle.



LwInK1K2:
Difference of the
SAS-signal between
the last 20 ms-cycle
and 20 ms-cycle
before.

Case 3

Monitoring Period



Continuous (After initialization
and no under voltage detected)

Enable Conditions



If value is higher than 665° + 90°
tolerance for more than 300 ms a
fault is determined.

Case 4

Monitoring Period



Continuous (during driving)

Enable Conditions



Based on a vehicle model a
reference SAS signal is build. The
difference between measured
SAS signal and SAS signal
calculated from yaw-rate sensor
signal is evaluated for fault
detection.

Dependent on the driving
conditions failures in size of [10 +
60 m/s / vehicle reference speed]
deg at steering angle are
recognized within 400 - 4800 ms
through three possible recognition
paths:

1. Curve Branch (lateral G > 2

m/s

2

and left and right

curve driving)

2008 Kia Sedona

2008 BRAKES ABS (Anti-Lock Brake System) - Sedona

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2. Stability Branch (no large

wheel speed differences
and stable acceleration)

3. Straight ahead Branch

(lateral G < 0.5 m/s

2

and

yaw rate < 2 deg/s).

The recognition time
depends on the active
branch (the time is shorter
in a relation 1.:2.:3.-4:2:1)
and the value of the
permissible time threshold
dependent on the deviation
between the compared
signals (small deviation -->
long detection time, large
deviation --> small
detection time).



Open or short of
steering angle
sensor circuit



Inoperative
steering angle
sensor



Inoperative

Case 5

Monitoring Period



Initialization once in every
ignition cycle.



The monitoring is active until a
reset by a change in the SAS
signal or until a right and left
cornering can be recognized.

Enable Conditions



If there is no change in the signal,
but a right and left cornering has
been recognized, a fault is
determined, (lateral G > 2 m/s

2

in

combination with a yaw rate >
6°/s in both directions).



At a minimum change of
e.g. 5° in the signal, the
monitoring is reset.

Case 6

Monitoring Period



Continuous (during driving)

Enable Conditions



The measured yaw rate and the
yaw rates, calculated from the
wheel speed sensor and SAS are
compared. If the signals don't fit
and forwards driving is detected,
a fault is determined.

Monitoring Period



Continuous (during driving)



Under normal conditions, two

2008 Kia Sedona

2008 BRAKES ABS (Anti-Lock Brake System) - Sedona

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MONITOR SCAN TOOL DATA

1. Connect scan tool to Data Link Connector (DLC).

2. Ignition "ON" & Engine "ON".

3. Turn the steering wheel to the left or right.

4. Monitor the "steering sensor" parameters on the scan tool.

Fig. 43: Scan Tool Display - EBD Warning Lamp
Courtesy of KIA MOTORS AMERICA, INC.

5. Whenever steering wheel is turned, is the steering sensor's scan tool data changed?

YES



Fault is intermittent caused by poor connection in steering sensor harness and/or HECU's connector
or was repaired and HECU memory was not cleared. Thoroughly check connectors for looseness,
poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as

Case 7

Enable Conditions

SAS messages are sent in one 20
ms cycle, which is shown by an
increase of the message counter
by 2. If the message counter
shows an increase higher than 3
or lower than 1 in one 20 ms-cyle,
a fault is stored after 160 ms.

HECU

Fail Safe



Reduced controller function
caused by inoperative SAS signal.
ABS/EBD control is available.



The ESC warning lamp is
activated.

2008 Kia Sedona

2008 BRAKES ABS (Anti-Lock Brake System) - Sedona

Microsoft

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© 2006 Mitchell Repair Information Company, LLC.