LEXUS SC400 1991 Service Repair Manual

LEXUS SC400 1991 Service Repair Manual SC400 1991 LEXUS LEXUS https://www.carmanualsonline.info/img/36/57051/w960_57051-0.png LEXUS SC400 1991 Service Repair Manual
Trending: engine oil capacity, brake pads replacement, air bleeding, maintenance schedule, oil viscosity, ground clearance, oil capacity

Page 3471 of 4087

LEXUS SC400 1991  Service Repair Manual 
DIAGNOSTIC CHART
DIAGNOSTIC
 CHART
HINT:  If diagnostic codes º22º (water temperature sensor circuit), º\
24º (intake air temperature sensorcircuit) and º41º (throttle position sensor circuit)

Page 3472 of 4087

LEXUS SC400 1991  Service Repair Manual 
NGOK
OKNG
OKNG
INSPECTION PROCEDURE
HINT:  If diagnostic codes º22º (water temperature sensor circuit), º\
24º (intake air temperature sensor circuit)and º41º (throttle position sensor circuit)

Page 3473 of 4087

LEXUS SC400 1991  Service Repair Manual 
±MEMO±TR±71
ENGINE TROUBLESHOOTING 
WhereEverybodyKnowsYourName

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LEXUS SC400 1991  Service Repair Manual 
Diag Code 25 26

Air±Fuel Ratio Lean Malfunction
Diag. Code 25, 26
Air±Fuel Ratio Rich Malfunction
CIRCUIT DESCRIPTION
Refer to page TR±62 for the circuit description.
Code No.
Diagnostic Code Det

Page 3475 of 4087

LEXUS SC400 1991  Service Repair Manual 
CIRCUIT DESCRIPTION (Contd)
DIAGNOSIS CODE DETECTION DRIVING PATTERN
Purpose  of the driving pattern.
(a)  To simulate diag. code detecting condition after diag. code is recorded.
(b)  To check that

Page 3476 of 4087

LEXUS SC400 1991  Service Repair Manual 
DIAGNOSTIC CHART
Check voltage of terminal VF.
Repair or replace harness or
connector.
Repair or replace.
Repair or replace.
Replace main oxygen sensor.
Repair or replace.
Repair or replace.
Replace

Page 3477 of 4087

LEXUS SC400 1991  Service Repair Manual 
NG
Type I
NG
Type II
NGOK
INSPECTION PROCEDURE
1Check voltage between terminals VF1, VF2 and E1 of check connector.
C
P
Cau-tion
1. Warm up engine at normal operating temperature
2. Connect  terminal

Page 3478 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
OKNG
OKNG
NGYES
3Check for open and short in harness and connector between engine (& ECT) EC\
U and main
oxygen  sensor, engine (& ECT) ECU and check connector (See page IN±27).
Repair or repla

Page 3479 of 4087

LEXUS SC400 1991  Service Repair Manual 
OKNG
OKNG
NGYES
7Check each item found to be a possible cause of problem.
Check each circuit found to be a possible cause of trouble according to the r\
esults of the check in . The
numbers in the t

Page 3480 of 4087

LEXUS SC400 1991  Service Repair Manual 
Diag. Code  24Intake Air Temp. Sensor Circuit
CIRCUIT DESCRIPTION
The intake air temp. sensor is built into the air flow meter and senses the\
 intake air temperature.
The structure of the sensor and
Trending: open gas tank, charging, air condition, ignition buzzer, fuse chart, windshield wipers, steering