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 (terminal No. 1) from the engine-ECU (terminal No. 54).
The power voltage is earthed to the engine-ECU (terminal No. 75) from the fuel temperature sensor (terminal No. 2).

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.

Judgment Criterion

The fuel temperature sensor output voltage is 0.10 V or less.

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

Item 21: Fuel temperature sensor

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. Connector check: B-130 fuel temperature sensor connector

Q. Is the check result normal?

	Go to Step 3 .

	Repair or replace the connector.

STEP 3. Check fuel temperature sensor itself.

Check fuel temperature sensor itself (Refer to ).

Q. Is the check result normal?

	Go to Step 4 .

	Replace the fuel temperature sensor.

STEP 4. Perform voltage measurement at B-130 fuel temperature sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: 4.5 - 4.9 V

Q. Is the check result normal?

	Go to Step 8 .

	Go to Step 5 .

STEP 5. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 6 .

	Repair or replace the connector.

STEP 6. Check harness between B-130 (terminal No. 1) fuel temperature sensor connector and D-213 (terminal No. 54) engine-ECU connector.

Check output line for short circuit.

Q. Is the check result normal?

	Go to Step 7 .

	Repair the damaged harness wire.

STEP 7. M.U.T.-III data list

Item 21: Fuel temperature sensor

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. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing

). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns

). After registering the injector identification code, the vehicle equipped with the DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration

STEP 8. Perform resistance measurement at B-130 fuel temperature sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal No. 2 and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 11 .

	Go to Step 9 .

STEP 9. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 10 .

	Repair or replace the connector.

STEP 10. Check harness between B-130 (terminal No. 2) fuel temperature sensor connector and D-213 (terminal No. 75) engine-ECU connector.

Check earthing line for damage.

Q. Is the check result normal?

	Go to Step 7 .

	Repair the damaged harness wire.

STEP 11. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 12 .

	Repair or replace the connector.

STEP 12. Check harness between B-130 (terminal No. 1) fuel temperature sensor connector and D-213 (terminal No. 54) engine-ECU connector.

Check output line for damage.

Q. Is the check result normal?

	Go to Step 7 .

	Repair the damaged harness wire.