Lexus SC300 / Lexus SC400. Manual - part 732

STARTER RELAY

INSPECTION OF STARTER RELAY

1. 

DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Work must be started after approx. 20 seconds or
longer from the time the ignition switch is turned to the
”LOCK” position and the negative (–) terminal cable is dis-
connected from the battery.

2. REMOVE 

STATER 

RELAY

LOCATION: In the engine compartment relay box.

3. INSPECT 

STARTER 

RELAY

A. Inspect relay continuity

(a)  Using an ohmmeter, check that there is continuity

between terminals 1 and 2.

(b)  Check that there is no continuity between terminals 3

and 5.

If continuity is not as specified, replace the relay.

B. Inspect relay operation

(a)  Apply battery voltage across terminals 1 and 2.
(b)  Using an ohmmeter, check that there is continuity

between terminals 3 and 5.

If operation is not as specified, replace the relay.

4. 

REINSTALL STARTER RELAY

5.  RECONNECT CABLE TO NEGATIVE TERMINAL OF

BATTERY

NEUTRAL START SWITCH

(See AT section)

THEFT DETERRENT SYSTEM

(See BE section)

–

STARTING SYSTEM

Starter Relay, Neutral Start Switch, Theft Deterrent
System

ST–35

SR–52

).

IN–33

).

WIRING DIAGRAM

Actuator Power Source Circuit

CIRCUIT DESCRIPTION

This is the power source for the motor.

DIAGNOSTIC CHART

DIAGNOSTIC CHART

SR–66

–

STEERING

STEERING COLUMN

NG

OK

OK

NG

INSPECTION PROCEDURE

1

Check voltage between terminals +B and GND of ECU connector.

C

OK

P

Remove ECU with connectors still connected.

Measure voltage between terminals +B and GND of
ECU connector.

Voltage:

10 – 14 V

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

SR–52

).

2

Check continuity between terminal GND of ECU connector and body ground.

OK

P

Measure resistance between terminal GND of ECU con-
nector and body ground.

Condition: Continuity

Repair or replace harness or connector.

Go to Step

.

–

STEERING

STEERING COLUMN

SR–67

OK

NG

3

Check PWR fusible link.

C

OK

P

Remove PWR fusible link from J/B No. 1.

Check continuity of PWR fusible link.

Continuity

Check for short in all the harness and components con-
nected to the PWR fusible link (See 

attached wiring dia-

gram

).

Check harness and connector between ECU and
battery (See page 

IN–33

).

SR–68

–

STEERING

STEERING COLUMN