Lexus SC300 / Lexus SC400. Manual — part 734

NG

OK

OK

NG

OK

NG

INSPECTION PROCEDURE

1

Check voltage between terminals TiS and E

1

of ECU connector.

C

OK

Hint

P

1.

Remove ECU with connectors still connected.

2.

Remove tilt sensor with connector still connected.

Measure voltage between terminals TiS and E

1

of ECU

connector, while turning tilt sensor lever slowly by hand
from raised side to lowered side.

Voltage:

Fully raised:

Below 1 V

Fully lowered:

4 – 6 V

In addition, as the lever is turned, the voltage should
increase gradually without interruption.

Proceed to next circuit inspection shown on matrix chart
(See page

SR–52

).

2

Check tilt position sensor.

C

OK

Hint

P

Disconnect tilt sensor connector.

Measure resistance between terminals 1 and 2 of tilt
sensor connector.

Resistance:

4 – 6

Measure resistance between terminals 3 and 2 of tilt
sensor connector, while turning tilt sensor lever slowly
by hand from raised side to lowered side.

Resistance:

Fully raised: Below 100

Fully lowered:

4 – 6

In addition, as the lever is turned, the resistance
should increase gradually without interruption.

Replace tilt position sensor.

3

Check harness and connectors between ECU and tilt position sensor (See page

IN–33

).

Repair harness or connector.

Check and replace ECU.

–

STEERING

STEERING COLUMN

SR–73

SR–52

).

IN–33).

WIRING DIAGRAM

Telescopic Position Sensor Circuit

CIRCUIT DESCRIPTION

The telescopic position is sent to the ECU as a voltage signal from the position sensor.
A constant 5 V is supplied to terminal 6 of the sensor.
The voltage at terminal 5 varies with position and is input to the ECU.

DIAGNOSTIC CHART

DIAGNOSTIC CHART

SR–76

–

STEERING

STEERING COLUMN

NG

OK

OK

NG

OK

NG

INSPECTION PROCEDURE

1

Check voltage between terminals TeS and E

1

of ECU connector.

C

OK

P

1.

Remove ECU with connectors still connected.

2.

Remove telescopic sensor with connectors still
connected.

Measure voltage between terminals TeS and E

1

of ECU

connector while turning telescopic sensor lever slowly
by hand from Contracted side to Extended side.

Voltage:

Fully forward:

0 – 1 V

Fully back:

4 – 5 V

In addition, as the lever is turned, the voltage should
increase gradually without interruption.

Proceed to next circuit inspection shown on matrix chart
(See page

SR–52

).

2

Check telescopic position sensor.

C

OK

P

OK

C

Disconnect telescopic sensor connector.

Measure resistance between terminals 3 and 6 of tele-
scopic sensor connector.

Resistance:

Approx. 5 k

Measure resistance between terminals 3 and 5 of tele-
scopic sensor connector while turning telescopic lever
slowly by hand from Contracted side to Extended side.

Resistance:

Fully forward:

0 – 1

Fully back:

4 – 5

In addition, as the lever is turned, the resistance
should increase gradually without interruption.

Replace tilt position sensor.

3

Check harness and connectors between ECU and tilt position sensor (See page

IN–33

).

Repair harness or connector.

Check and replace ECU.

–

STEERING

STEERING COLUMN

SR–77

SR–52

).

IN–33

).

WIRING DIAGRAM

Telescopic Motor Circuit

CIRCUIT DESCRIPTION

The ECU provides both + B and ground for the telescopic motor.
Reversing polarity of the applied voltage reverses the motor.

ÑÑÑÑ

ÑÑÑÑ

TeM

+

ÑÑÑÑ

ÑÑÑÑ

TeM

–

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Rotation

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

Telescopic

ÑÑÑÑ

ÑÑÑÑ

ÑÑÑÑ

+

ÑÑÑÑ

ÑÑÑÑ

ÑÑÑÑ

–

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Clockwise

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

Contracted

ÑÑÑÑ

ÑÑÑÑ

–

ÑÑÑÑ

ÑÑÑÑ

+

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Counterclockwise

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

Extended

DIAGNOSTIC CHART

DIAGNOSTIC CHART

SR–78

–

STEERING

STEERING COLUMN