Engine Controls For California
DTC P0181 FTT SENSOR
Component Description
The fuel tank temperature sensor (4) is used to detect the fuel temperature inside the fuel tank. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the fuel temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.
- Fuel level sensor unit and fuel pump (1)
- Fuel pressure regulator (2)
- Fuel level sensor (3)
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result damage the ECM's transistor. Use ground other than ECM, such as ground.
On Board Diagnosis Logic
DTC Confirmation Procedure
1. INSPECTION START
Is it necessary to erase permanent DTC?
YES- GO TO 7.
NO- GO TO 2.
2. PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.
1.Turn ignition switch OFF and wait at least 10 seconds.
2.Turn ignition switch ON.
3.Turn ignition switch OFF and wait at least 10 seconds.
- GO TO 3.
3. PERFORM DTC CONFIRMATION PROCEDURE-I
1.Turn ignition switch ON and wait at least 10 seconds.
2.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- .
NO- GO TO 4.
4. CHECK ENGINE COOLANT TEMPERATURE
With CONSULT
1.Select "COOLAN TEMP/S" in "DATA MONITOR" mode with CONSULT.
2.Check "COOLAN TEMP/S" indication.
With GST
Follow the procedure "With CONSULT" above.
Is "COOLAN TEMP/S" indication less than 60�C (140�F)?
YES- INSPECTION END
NO- GO TO 5.
5. PERFORM DTC CONFIRMATION PROCEDURE-II
With CONSULT
1.Cool engine down until "COOLAN TEMP/S" indication is less than 60�C (140�F).
2.Wait at least 10 seconds.
3.Check 1st trip DTC.
With GST
Follow the procedure "With CONSULT" above.
Is 1st trip DTC detected?
YES- .
NO- GO TO 6.
6. PERFORM OVERALL FUNCTION CHECK (FOR MALFUNCTION B)
Perform overall function check. Engine Controls.
NOTE:
Use the overall function check to check the overall function of the FTT sensor circuit. During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES- INSPECTION END
NO- Proceed to .
7. PRECONDITIONING
If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following procedure before conducting the next test.
1.Turn ignition switch OFF and wait at least 10 seconds.
2.Turn ignition switch ON.
3.Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
-Before performing the following procedure, do not add fuel.
-Before performing the following procedure, check that fuel level is between 1/4 and 4/4.
-Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
- GO TO 8.
8. PERFORM DTC CONFIRMATION PROCEDURE B
1.Start engine and let it idle for 60 minutes.
2.Move the vehicle to a cool place.
NOTE:
Cool the vehicle in an environment of ambient air temperature between 10�C (14�F) and 35�C (95�F).
3.Turn ignition switch OFF and soak the vehicle for 12 hours.
CAUTION:
Never turn ignition switch ON during soaking.
NOTE:
The vehicle must be cooled with the food open.
4.Start engine and let it idle for 5 minutes or more.
CAUTION:
Never turn ignition switch OFF during idling.
5.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to .
NO- INSPECTION END
Overall Function Check
1. CHECK FUEL TANK TEMPERATURE (FTT) SENSOR
1.Turn ignition switch OFF.
2.Disconnect fuel level sensor unit and fuel pump harness connector.
3.Remove fuel level sensor unit. Removal and Installation.
4.Check resistance between fuel level sensor unit and fuel pump terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES- GO TO 2.
NO- Proceed to .
2. CHECK INTERMITTENT INCIDENT
Check intermittent incident. For California.
Is the inspection result normal?
YES- INSPECTION END
NO- Proceed to .
Wiring Diagram
Diagnosis Procedure
1. INSPECTION START
Confirm the detected malfunction (A or B). .
Which malfunction is detected?
A - GO TO 2.
B - GO TO 7.
2. CHECK GROUND CONNECTIONS
1.Turn ignition switch OFF.
2.Loosen and retighten ground screws on the body.
For California.
-White arrow indicates : Vehicle front
-Body ground (1)
OK or NG
OK- GO TO 3.
NG- Repair or replace ground connections.
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1.Turn ignition switch OFF.
2.Disconnect "fuel level sensor unit and fuel pump" harness connector (1).
-White arrow indicates : Vehicle front
3.Turn ignition switch ON.
4.Check voltage between "fuel level sensor unit and fuel pump"
terminal 4 and ground with CONSULT or tester.
Voltage: Approximately 5 V
OK or NG
OK- GO TO 5.
NG- GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B9, E13
- Harness connectors E3, F2
- Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
- Repair open circuit or short to ground or short to power in harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1.Turn ignition switch OFF.
2.Disconnect combination meter harness connector.
3.Check harness continuity between "fuel level sensor unit and fuel pump" terminal 5 and combination meter terminal 4, ECM terminal 60. Refer to Wiring Diagram.
Continuity should exist.
4.Also check harness for short to ground and short to power.
OK or NG
OK- GO TO 7.
NG- GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B8, M8
- Harness connectors B9, E13
- Harness connectors E3, F2
- Harness for open or short between "fuel level sensor unit and fuel pump" and combination meter.
- Harness for open or short between "fuel level sensor unit and fuel pump" and ECM.
- Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to, .
OK or NG
OK- GO TO 8.
NG- Replace "fuel level sensor unit and fuel pump".
8. CHECK INTERMITTENT INCIDENT
Perform Trouble Diagnosis For Intermittent Incident
-INSPECTION END
Component Inspection
FUEL TANK TEMPERATURE SENSOR
1.Check resistance between "fuel level sensor unit and fuel pump"
terminal 4 and 5 by heating with hot water as shown in the figure.
2.If NG, replace "fuel level sensor unit and fuel pump".