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2nd coast
brake (B
1)
Forward clutch
(C1)
Front and rear
planetary gear unitDirect clutch
(C2)
2nd brake (B
2)
No.2 one±way
clutch (F
2)
No.1 one±way
clutch (F
1)
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±69
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WIRING DIAGRAM CIRCUIT INSPECTION
DTC 38 A T Fluid Temperature Sensor Circuit
CIRCUIT DESCRIPTION
The fluid temp. sensor converts fluid temp. into resistance values which is input into the ECM.
DTC No. Diagnostic Trouble Code Detection Condition Trouble Area
38
Either (a) or (b) are detected for 0.5 sec. or
more.
(a) Temp. sensor resistance less 79
(b) After the engine has been operating for 15
minutes or more, the resistance at the
temp. sensor is more than 156 k
Harness or connector between A/T fluid
temp. sensor and ECM
A/T fluid temp. sensor
ECM
AT2±70± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING
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INSPECTION PROCEDURE
Check A/T fluid temp. sensor.
Check harness and connector between A/T fluid temp. sensor and ECM
(See page IN±30).
Replace A/T fluid temp. sensor.
Repair or replace harness or connector.
Check sensor resistance
Remove A/T fluid temp. sensor.
Measure resistance between terminals of A/T fluid
temp. sensor at 20°C (68°F) and 110°C (230°F).
Resistance:
20°C (68°F): Approx. 12.08 k
11 0°C (230°F): Approx. 0.78 k
20°C (68°F) and 110°C (230°F).
Check and replace ECM.
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±71
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CIRCUIT DESCRIPTION
Transmission
Output Shaft
No.1 Vehicle
Speed Sensor
The No. 1 vehicle speed sensor outputs a 4±pulse signal for every revolution of the rotor shaft, which
is rotated by the transmission output shaft via the driven gear. After this signal is converted into a more
precise rectangular waveform by the waveform shaping circuit inside the combination meter, it is then
transmitted to the engine control module. The ECM determines the vehicle speed based on the fre-
quency of these pulse signals.
Diagnostic Trouble Code Detection ConditionDTC No.Trouble Area
42
No. 1 vehicle Speed sensor
Telltale light RH
Harness or connector between No. 1 vehicle
speed sensor and ECM
ECMAll conditions below are detected for 4 secs. or
more. (2 trips detection logic)*
(a) No No.1 vehicle speed sensor signal in 16
pulses of No.2 vehicle speed sensor signal.
(b) Vehicle speed: 9 km/h (5.6 mph) or more
(c) Park/neutral position switch:
OFF (Other than P or N position)
HINT: In test mode, diagnostic trouble code 42 is output when vehicle speed is 5 km/h (3 mph) or
below.
Waveform between terminals SP1 and E2 when vehicle speed is approx. 20 km/h (12 mph).
HINT: As the vehicle's speed increases, the signal output from
SP1 increases.
* See page AT2±58
Driven Gear
No.1 Vehicle Speed Sensor
Telltale Light
RH
DTC 42 No.1 Vehicle Speed Sensor Signal Circuit
AT2±72± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING
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WIRING DIAGRAM
Check voltage between terminal SP1 of ECM connector and body ground.
Check operation of odometer and trip meter (telltale light RH
(See page BE±48)).
Check and replace ECM.
Repair or replace harness or connector between
ECM and telltale light RH.
Go to
1. Shift the shift lever to N position
2. Jack up one of the rear wheels.
3. Connect the Check Harness A.
See page EG±510)
(1) Disconnect power steering ECU connector
and cruise control ECU connector.
(5) Turn ignition switch ON.
Measure voltage between terminal SP1 of ECM
connector and body ground when the wheel is
turned slowly.
Voltage is generated intermittently.
INSPECTION PROCEDURE
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±73
Page 558 of 2543
Check operation of No.1 vehicle speed sensor (see page BE±46).
Repair or replace harness or connector between
telltale light RH and No.1 vehicle speed sensor.
Replace No.1 vehicle speed sensor.
AT2±74± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING
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The No.4 solenoid valve controls the hydraulic pressure acting on
the brakes and clutches of the planetary gear units when gears are
shifted and performs smooth gear shifting.
The ECM determines optimum operating pressure according to
the signals from the throttle position sensor, vehicle speed sensor
and O/D clutch speed sensor and controls the volume of current
flow to the solenoid valve.
The amount of electric current to the solenoid is controlled by the
(*) duty ratio of ECM output signals, causing momentary change
to the hydraulic pressure acting on the clutches during gear shift-
ing. When the duty ratio is high, the hydraulic pressure acting on
the clutches is now.
(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B is the period of non±continuity, then
Diagnostic Trouble Code Detection ConditionDTC No.Trouble Area
46
No. 4 solenoid valve
Harness or connector between No.4
solenoid valve and ECM
ECMAll conditions below are detected for 1 sec. or
more. (2 trips detection logic)*
(a) ECM outputs duty signal to No.4 solenoid in
90% or higher duty ratio.
(b) Current to No.4 solenoid:
330 + 100 mA or less
(O/D OFF indicator light doesn't blink)
* See page AT2±58
Waveform between terminals SLN
and E1 when engine is idling. Waveform between terminals SLN
and E1 during shift change.
Lock±up
operation
pressure
Current flow to
solenoid
Duty Ratio =
CIRCUIT DESCRIPTION
100 (%)
DTC 46 No.4 Solenoid Valve Circuit (For Accumulator Back
Pressure Modulation)
± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTINGAT2±75
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WIRING DIAGRAM
AT2±76± A340E (2JZÐGTE) AUTOMATIC TRANSMISSIONTROUBLESHOOTING