Code No. P0182: Fuel Temperature Sensor Circuit Low input
OPERATION
- A power voltage of 5 V is applied to the fuel temperature sensor output terminal
from the engine-ECU connector terminal FTS.
- The power voltage is earthed to the engine-ECU connector terminal FTSE from the
fuel temperature sensor connector terminal.
FUNCTION
- The fuel temperature sensor converts the fuel temperature into a voltage
and inputs the voltage signal to the engine-ECU.
- In response to the signal, the engine-ECU corrects the fuel injection amount, etc.
- The fuel temperature sensor is a kind of resistor, which has characteristics to
reduce its resistance as the fuel temperature rises. Therefore, the sensor output voltage varies
with the fuel temperature, and becomes lower as the fuel temperature rises.
TROUBLE JUDGMENT
Check Conditions
- Battery positive voltage is 8 - 16 V
- 2 seconds later after the ignition switch has been in "ON" position or the engine
has started up.
- The fuel temperature sensor output voltage is 0.10 V or less.
FAIL-SAFE AND BACKUP FUNCTION
- The fuel temperature is controlled to be 45°C (Start-up of -25°C)
- The AS&G control is prohibited.
PROBABLE CAUSES
- Failed fuel temperature sensor
- Short circuit in fuel temperature sensor circuit or loose connector contact
- Failed engine-ECU
DIAGNOSTIC PROCEDURE |
STEP 1. M.U.T.-III data list |
|
OK: At ambient temperature (fuel temperature) or equivalent. |
Q.
Is the check result normal?
|
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunctions ). |
|
Go to Step 2. |
|
STEP 2. Check fuel temperature sensor itself. |
Q.
Is the check result normal?
|
Go to Step 3. |
|
Repair or replace the connector, or replace the fuel temperature sensor. |
|
STEP 3. Perform voltage measurement at fuel temperature sensor connector. |
|
OK: 4.5 - 4.9 V |
Q.
Is the check result normal?
|
Go to Step 6. |
|
Go to Step 4. |
|
STEP 4. Check harness between fuel temperature sensor connector terminal and engine-ECU connector terminal FTS. |
|
Q.
Is the check result normal?
|
Go to Step 5. |
|
Repair or replace the connector, or repair the damaged harness wire. |
|
STEP 5. M.U.T.-III data list |
|
OK: At ambient temperature (fuel temperature) or equivalent. |
Q.
Is the check result normal?
|
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunctions ). |
|
Replace the engine-ECU. |
|
STEP 6. Perform resistance measurement at fuel temperature sensor connector. |
|
OK: Continuity (2 Ω or less) |
Q.
Is the check result normal?
|
Go to Step 8. |
|
Go to Step 7. |
|
STEP 7. Check harness between fuel temperature sensor connector terminal and engine-ECU connector terminal FTSE. |
|
Q.
Is the check result normal?
|
Go to Step 5. |
|
Repair or replace the connector, or repair the damaged harness wire. |
|
STEP 8. Check harness between fuel temperature sensor connector terminal and engine-ECU connector terminal FTS. |
|
Q.
Is the check result normal?
|
Go to Step 5. |
|
Repair or replace the connector, or repair the damaged harness wire. |
|