Lexus SC300 / Lexus SC400. Service manual — part 737

–MEMO–

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STEERING

STEERING COLUMN

SR–87

SR–52

).

IN–33).

WIRING DIAGRAM

Set Switch Circuit

CIRCUIT DESCRIPTION

When switch 1 or 2 is pushed while SET switch is being pushed ON in memory operation, a signal is sent
to the ECU to memorize the present positions of the tilt, telescopic, seat and mirror.

DIAGNOSTIC CHART

DIAGNOSTIC CHART

SR–88

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STEERING

STEERING COLUMN

NG

OK

OK

NG

OK

NG

INSPECTION PROCEDURE

1

Check voltage between terminals MRY and ECU–E of ECU connector.

C

OK

P

Remove ECU with connectors still connected.

Measure voltage between terminals MRY and ECU–E
of ECU connector when SET switch is on and off.

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

SR–52

).

2

Check set switch.

C

OK

P

Disconnect driving position memory & return switches
connector.

Measure resistance between terminals 3 and 4 of driv-
ing position memory & return switches connector when
SET switch is on and off.

Replace memory & return switches.

3

Check harness and connector between ECU and driving position memory & return switches
(See page

IN–33

).

Repair or replace harness or connector.

Check and replace ECU.

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STEERING

STEERING COLUMN

SR–89

SR–52

).

IN–33).

WIRING DIAGRAM

Memory & Return Switches Circuit

CIRCUIT DESCRIPTION

A memory command signal when switch 1 or 2 pushed while SET
switch is being pushed ON or a return command signal when
switch 1 or 2 is pushed ON is sent to the ECU for memory and re-
turn operations of the tilt, telescopic, seat and mirror.

DIAGNOSTIC CHART

DIAGNOSTIC CHART

SR–90

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STEERING

STEERING COLUMN