DTC P0118:00

ECT sensor No.1 circuit high input

DETECTION CONDITION

• The PCM monitors the ECT sensor No.1 signal. If the PCM detects that the ECT sensor No.1 voltage at the PCM terminal 1AK is above 4.9 V for 5 s, the PCM determines that the ECT sensor No.1 circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (engine cooling system).

• The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Fixes the water temperature for the engine control at 40 °C {104 °F}, and for the idle air control at 80 °C {176 °F}.

• Operates the cooling fan (high speed rotation).

• Inhibits the fuel cut control during shift change.

POSSIBLE CAUSE

• ECT sensor No.1 connector or terminals malfunction

• ECT sensor No.1 malfunction

• PCM connector or terminals malfunction

• Short to power supply in wiring harness between ECT sensor No.1 terminal A and PCM terminal 1AK

• Open circuit in wiring harness between the following terminals:

• ECT sensor No.1 terminal A—PCM terminal 1AK

• ECT sensor No.1 terminal B—PCM terminal 1AM

• PCM malfunction

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

ECT

°C, °F

Engine coolant temperature (No.1)

• Displays ECT

V

• ECT is 20 °C {68 °F}: Approx. 3.10 V

• ECT is 40 °C {104 °F}: Approx. 2.16 V

• ECT is 60 °C {140 °F}: Approx. 1.40 V

• ECT is 80 °C {176 °F}: Approx. 0.87 V

• ECT is 100 °C {212 °F}: Approx. 0.54 V

STEP

INSPECTION

ACTION

1

• Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (engine cooling system related) been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off.

• Disconnect the ECT sensor No.1 connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 8.

No

Go to the next step.

4

• Verify that the ECT sensor No.1 connector is disconnected.

• Access the ECT PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Connect a jumper wire between ECT sensor No.1 terminals A and B (wiring harness-side).

• Verify the ECT PID value.

• Is the voltage 4.6 V or below?

Yes

Replace the ECT sensor No.1, then go to Step 8.

(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

5

• Switch the ignition off.

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 8.

No

Go to the next step.

6

• Verify that the ECT sensor No.1 and PCM connectors are disconnected.

• Switch the ignition ON (engine off).

• Measure the voltage at the ECT sensor No.1 terminal A (wiring harness-side).

• Is the voltage 0 V?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between ECT sensor No.1 terminal A and PCM terminal 1AK.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 8.

7

• Verify that the ECT sensor No.1 and PCM connectors are disconnected.

• Switch the ignition off.

• Inspect for continuity between the following terminals (wiring harness-side):

• ECT sensor No.1 terminal A—PCM terminal 1AK

• ECT sensor No.1 terminal B—PCM terminal 1AM

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• ECT sensor No.1 terminal A—PCM terminal 1AK

• ECT sensor No.1 terminal B—PCM terminal 1AM

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to the next step.

8

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [SKYACTIV-G 2.5].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to the next step.

No

Go to the next step.

9

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.