Code No.15: A/T fluid temperature sensor system
OPERATION
- The A/T fluid temperature sensor converts the automatic
fluid temperature to voltage, and send the information to the
engine-A/T-ECU.
- The A/T fluid temperature rises, the resistance decreases.
Thus, the sensor output voltage depends on the automatic fluid
temperature. As the A/T fluid temperature rises, the
output voltage will decrease.
DIAGNOSIS CODE SET CONDITIONS
If the A/T fluid
temperature sensor output voltage is 4.5 volts or more after driving for
10 minutes or more, there is an open circuit in the A/T fluid
temperature sensor and diagnosis code 15 is set.
PROBABLE CAUSES
- Malfunction of the A/T fluid temperature sensor
- Damaged harness wires and connectors
- Malfunction of the engine-A/T-ECU
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STEP 1. M.U.T.-III data list
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Item 15: A/T fluid
temperature sensor (Refer to Data List Table ).
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Q.
Is the check result normal?
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Intermittent
malfunction (Refer to GROUP 00 - How to Cope with
Intermittent Malfunction ).
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Go to Step
2.
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STEP 2. Measure the resistance at A/T control
solenoid valve assembly connector B-109.
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![](../../../img/23/AC303628AF00ENG.png)
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Disconnect the connector, and
measure the resistance between terminal 1 and 2 at the
sensor side. OK:
- 16.7 - 20.5 kΩ (at
0°C)
- 7.3 - 8.9 kΩ (at
20°C)
- 3.4 - 4.2 kΩ (at
40°C)
- 1.9 - 2.2 kΩ (at
60°C)
- 1.0 - 1.2 kΩ (at
80°C)
- 0.57 - 0.69 kΩ (at
100°C)
Q.
Is the check result normal?
Go to Step
3.
Replace
the A/T fluid temperature sensor.
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STEP 3. Connector check: B-109 A/T control
solenoid valve assembly
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![](../../../img/23/AC303628AG00ENG.png)
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Check for the contact with
terminals.
Q.
Is the check result normal?
Go to Step
4.
Repair
the defective connector.
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STEP 4. Measure the resistance at A/T control
solenoid valve assembly connector B-109.
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![](../../../img/23/AC303628AG00ENG.png)
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Disconnect the connector, and
measure the resistance between terminal 2 and earth at the
wiring harness side. OK: 2 Ω or
less
Q.
Is the check result normal?
Go to Step
9.
Go to Step
5.
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STEP 5. Measure the voltage at engine-A/T-ECU
connector C-113.
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(1)Connect A/T control solenoid valve assembly
connector B-109.
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(2)Turn the ignition switch to the ON
position.
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![](../../../img/23/AC311284AF00ENG.png)
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(3)Measure the voltage between
engine-A/T-ECU connector C-113 terminal No.96 and
earth. OK: 0.5 V or less
Q.
Is the check result normal?
Go to Step
8.
Go to Step
6.
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STEP 6. Connector check: C-113 engine-A/T-ECU
connector
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![](../../../img/23/AC311284AF00ENG.png)
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Check for the contact with
terminals.
Q.
Is the check result normal?
Go to Step
7.
Repair
the defective connector.
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STEP 7. M.U.T.-III data list
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Item 15: A/T fluid
temperature sensor (Refer to Data List Table ).
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|
Q.
Is the check result normal?
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|
Intermittent
malfunction (Refer to GROUP 00 - How to Cope with
Intermittent Malfunction ).
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Replace the
engine-A/T-ECU.
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STEP 8. Connector check: C-113 engine-A/T-ECU
connector
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![](../../../img/23/AC311284AF00ENG.png)
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Check for the contact with
terminals.
Q.
Is the check result normal?
Go to Step
14.
Repair
the defective connector.
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STEP 9. Measure the voltage at A/T control
solenoid valve assembly connector B-109.
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![](../../../img/23/AC303628AG00ENG.png)
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(1)Disconnect the connector, and
measure the voltage between terminal 1 and earth at the
wiring harness side. (2)Turn the ignition switch to the
ON position. OK: 4.5 - 4.9
V
Q.
Is the check result normal?
Go to Step
7.
Go to Step
10.
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STEP 10. Measure the voltage at engine-A/T-ECU
connector C-113.
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(1)Connect A/T control solenoid valve assembly
connector B-109.
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(2)Turn the ignition switch to the ON
position.
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![](../../../img/23/AC311284AF00ENG.png)
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(3)Measure the voltage between
engine-A/T-ECU connector C-113 terminal No.119 and
earth. OK:
- 3.8 - 4.0 V (at 20°C)
- 3.2 - 3.4 V (at 40°C)
- 1.7 - 1.9 V (at 80°C)
Q.
Is the check result normal?
Go to Step
12.
Go to Step
11.
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STEP 11. Connector check: C-113 engine-A/T-ECU
connector
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![](../../../img/23/AC311284AF00ENG.png)
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Check for the contact with
terminals.
Q.
Is the check result normal?
Go to Step
7.
Repair
the defective connector.
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STEP 12. Connector check: C-113 engine-A/T-ECU
connector
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![](../../../img/23/AC311284AF00ENG.png)
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Check for the contact with
terminals.
Q.
Is the check result normal?
Go to Step
13.
Repair
the defective connector.
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STEP 13. Check the harness between A/T control
solenoid valve assembly connector B-109 terminal No.1
and engine-A/T-ECU connector C-113 terminal
No.119.
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![](../../../img/23/AC303628AG00ENG.png)
![](../../../img/23/AC311284AF00ENG.png)
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Check the output line for
short-circuited or open circuit.
Q.
Is the check result normal?
Go to Step
7.
Repair
the wiring harness.
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STEP 14. Check the harness between A/T control
solenoid valve assembly connector B-109 terminal No.2
and engine-A/T-ECU connector C-113 terminal
No.96.
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![](../../../img/23/AC303628AG00ENG.png)
![](../../../img/23/AC311284AF00ENG.png)
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Check the earth line for open
circuit.
Q.
Is the check result normal?
Go to Step
7.
Repair
the wiring harness.
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