P0117

DTC P0115, P0117, or P0118

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0115
- Engine Coolant Temperature (ECT) Sensor Circuit

DTC P0117
- Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage

DTC P0118
- Engine Coolant Temperature (ECT) Sensor Circuit High Voltage

Diagnostic Fault Information





Typical Scan Tool Data





Circuit Description

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and supplies a ground to the low reference circuit.

The following table illustrates the difference between temperature, resistance, and voltage:





Conditions for Running the DTC

P0115, P0117, or P0118
* The ignition is ON or the engine is operating.
* The DTC runs continuously once the above condition is met.

Conditions for Setting the DTC

P0115
* The PCM detects that the ECT sensor is colder than -39°C (-38°F) for greater than 0.5 seconds.
OR
* The PCM detects that the ECT sensor is greater than 139°C (282°F) for greater than 0.5 seconds.

P0117

The PCM detects that the ECT sensor is greater than 139°C (282°F) for greater than 0.5 seconds.

P0118

The PCM detects that the ECT sensor is colder than -39°C (-38°F) for greater than 0.5 seconds.

Action Taken When the DTC Sets

* DTC P0115, P0117 and P0118 are Type A DTCs.
* The PCM enters the Fail-Safe function and the engine coolant temperature defaults to 80°C (176°F).

Conditions for Clearing the MIL/DTC

DTC P0115, P0117 and P0118 are Type A DTCs.

Diagnostic Aids

* If the vehicle has sat overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F).
* After starting a cold engine, the ECT sensor temperature should rise steadily, then stabilize after the thermostat opens.
* High resistance in the circuit of the ECT sensor could set a DTC.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Engine idling for 1 minute, observe the DTC information with a scan tool. DTCs P0115, P0117 and P0118 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the engine coolant temperature (ECT) sensor.
2. Test for less than 10 ohm between the low reference circuit terminal 1 and ground G104.

• If greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests normal, replace the PCM.

3. Ignition ON, verify that the ECT sensor parameter is at -40°C (-40°F).

• If warmer than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the PCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the ECT sensor parameter is greater than 139°C (280°F).

• If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

5. If all circuits test normal, test or replace the ECT sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the ECT sensor.

Note: A thermometer can be used to test the sensor off the vehicle.

2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance (Temperature Versus Resistance) table and verify that the resistance is within 5 percent of the specification.

• If not within the specified range, replace the ECT sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Engine Coolant Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for control module replacement, setup, and programming