Lexus SC300 / Lexus SC400. Manual - part 85

OK

NG

2

Check harness and connector between battery and No. 4 solenoid valve, No. 4 solenoid valve
and ECM (See page IN–33).

Repair or replace harness or connector.

Proceed to next circuit inspection shown on ma-
trix chart (See page AT–66). However, when diag.
trouble code 64 is display, check and replace ECM.

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A304E (1UZ–FE) AUTOMATIC TRANSMISSION

TROUBLESHOOTING

AT–97

This sensor detects the rotation speed of the O/D input shaft from the
rotation of the O/D direct clutch drum.
Its construction is the same as that of the No. 2 vehicle speed sensor
(See page AT–86).
By comparing the O/D direct clutch speed signal and the No. 2 vehicle
speed sensor signal, ECM detects the shift timing of the gears and ap-
propriately controls the engine torque and hydraulic pressure in re-
sponse to various conditions, thus performing smooth gear shift.

DTC

67

O/D Direct Clutch Speed Sensor Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

67

All conditions below are detected for 4 secs. or more

2 trip detection logic*

(a) Gear position: 1st, 2nd and 3rd

(b) T/M input shaft rpm: 100 rmp or more

(c) T/M output shaft rpm: less than 300 rpm

(d) PNP: OFF (other than P or N position)

 O/D direct clutch speed sensor.

 Harness or connector between O/D direct

clutch speed sensor and ECM.

 ECM

*: See page AT–62.

Reference

 Wave form between terminals NCO

+

  and NCO

–

 during engine idling.

AT–98

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A304E (1UZ–FE) AUTOMATIC TRANSMISSION

TROUBLESHOOTING

AT–66

IN–33

WIRING DIAGRAM

DIAGNOSTIC CHART

DIAGNOSTIC CHART

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A304E (1UZ–FE) AUTOMATIC TRANSMISSION

TROUBLESHOOTING

AT–99

NG

NG

OK

NG

INSPECTION PROCEDURE

1

Check resistance between terminals NCO

+

 and NCO

–

 of ECM connector.

C

OK

P

Connect the check harness A to the ECM (See EG sec-
tion).

Check resistance between terminals NCO

+

 and NCO

–

of ECM connector.

Resistance:

560 – 680 

Proceed to next circuit inspection shown on matrix chart
(See page AT–66). However, when diag. trouble code 67
is displayed, check and replace ECM.

2

Check O/D direct clutch speed sensor.

C

OK

Hint

P

OK

C

Remove O/D direct clutch speed sensor from transmis-
sion (See page AT–17).

Measure resistance between terminals 1 and 2 of O/D
direct clutch speed sensor.

Resistance:

560 – 680 

Reference

Check the speed sensor function

Check voltage between terminals 1 and 2 of the speed
sensor when a magnet is put close to the front end of the
speed sensor then taken away quickly.

Voltage is generated intermittently.

The voltage generated is extremely low.

Replace O/D direct clutch speed sensor.

Check and repair harness and connector between
ECM and O/D direct clutch speed sensor (See
page IN–33).

AT–100

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A304E (1UZ–FE) AUTOMATIC TRANSMISSION

TROUBLESHOOTING