ect LEXUS SC300 1991 Service Repair Manual

NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals TiS and E1 of ECU connector.
C
OK
Hint
P1. 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).
2Check tilt position sensor.
C
OK
Hint
PDisconnect 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.
3Check harness and connectors between ECU and tilt position sensor (See \
page IN±33).
Repair harness or connector.
Check and replace ECU.
±
STEERING STEERING COLUMNSR±73
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NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals TeS and E1 of ECU connector.
C
OK
P1. Remove ECU with connectors still connected.
2. Remove telescopic sensor with connectors stillconnected.
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).
2Check 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.
3Check harness and connectors between ECU and tilt position sensor (See \
page IN±33).
Repair harness or connector.
Check and replace ECU.
±
STEERING STEERING COLUMNSR±77
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OKNG
OKNG
INSPECTION PROCEDURE
1Check telescopic motor.
C
PDisconnect telescopic motor connector.
Connect positive (negative ) terminal to terminal
1 of telescopic motor connector and negative  (posi-
tive ) terminal to terminal 2.
Replace telescopic motor.
2Check harness and connector between ECU and telescopic motor (See page \
IN±33).
Repair or replace harness or connector.
Proceed to next circuit inspection shown on ma-
trix chart (See page SR±52).
±
STEERING STEERING COLUMNSR±79
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NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals ASW and E1 of ECU connector.
C
OK
PRemove ECU with connectors still connected.
Measure voltage between terminals ASW and E
1 of
ECU connector when auto switch is on and off.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52).
2Check auto set switch.
C
OK
PDisconnect combination switch connector.
Measure resistance between terminals 2 (7) and 6 (8)
of combination switch connector when auto switch is on
and off.
( ): SC300
Replace tilt & telescopic switch.
Go to Step

±
STEERING STEERING COLUMNSR±81
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OKNG
3Check harness and connector between ECU and tilt & telescopic switch (See pa\
ge IN±33).
Repair or replace harness or connector.
Check and replace ECU.
SR±82±
STEERING STEERING COLUMN
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NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals VC and MSW of ECU connector.
C
OK
PRemove ECU with connectors still connected.
Measure voltage between terminals V
C and MSW of
ECU connector when manual switch is operated.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52).
2Check manual switch.
C
OK
PDisconnect combination switch connector.
Measure resistance between terminals 3 (4) and 5 (6)
of combination switch connector when manual switch is
operated.
( ): SC200
Replace tilt & telescopic switch.
Go to Step
.
±
STEERING STEERING COLUMNSR±85
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OKNG
3Check harness and connector between ECU and tilt & telescopic switch (See pa\
ge IN±33).
Replace tilt & telescopic switch.
Check and replace ECU.
SR±86±
STEERING STEERING COLUMN
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NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals MRY and ECU±E of ECU connector.
C
OK
PRemove 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).
2Check set switch.
C
OK
PDisconnect 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.
3Check 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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NGOK
OKNG
OKNG
INSPECTION PROCEDURE
1Check voltage between terminals M1, M2 and ECU±E of ECU connector.
C
OK
PRemove ECU with connectors still connected.
Measure voltage between terminals M1, M2 and ECU±
E of ECU connector when memory & return switches is
on and off.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52).
2Check memory & return switches.
C
OK
PDisconnect driving position memory & return switches
connector.
Measure resistance between terminals M2, M1 and E of
driving position memory & return switches connector
when memory & return switches is on and off.
Replace memory & return switches.
3Check harness and connector between ECU and memory & return switches (See pa\
ge IN±33).
Repair or replace harness or connector.
Check and replace ECU.
±
STEERING STEERING COLUMNSR±91
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NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminal IG of ECU connector and body ground.
C
OK
PRemove ECU with connectors still connected.
Measure voltage between terminal EG of ECU connec-
tor and body ground when ignition switch is on and off.
Proceed to next circuit inspection shown on matrix chart
(See page SR±52.)
2Check ECU±IG fuse.
C
OK
PRemove ECU±IG fuse from J/B No. 1.
Check continuity of ECU±IG fuse.
Continuity
Check for short in all the harness and components con-
nected to ECU±IG fuse.
Check and repair harness or connector between
ECU and battery.
±
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