P1115

DTC P1114 or P1115

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptors

DTC P1114
- Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage

DTC P1115
- Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

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




The table illustrates the difference between temperature, resistance, and voltage.

Conditions for Running the DTCs

* The engine has been running for greater than 2 minutes.
* The DTCs run continuously when the above condition is met.

Conditions for Setting the DTC

P1114

The ECM detects that the ECT sensor is greater than 149°C (300°F ) intermittently.

P1115

The ECM detects that the ECT sensor is less than -38°C (-34°F) intermittently.

Action Taken When the DTC Sets

DTCs P1114 and P1115 are Type C DTCs.

Conditions for Clearing the MIL/DTC

DTCs P1114 and P1115 are Type C DTCs.

Circuit/System Verification

1. Verify that DTCs P0117 or P0118 are not set.

• If any of the DTCs are set, Refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions

2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. DTC P1114 or P1115 should not set.
3. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

Circuit/System Testing

1. Start the engine. Observe the engine coolant temperature (ECT) sensor parameter while moving the harness connector of the sensor. The ECT sensor parameter should not change abruptly.

• If the ECT sensor parameter changes abruptly, repair the harness connector of the ECT sensor.

2. Engine running, observe the ECT sensor parameter while moving the harness connector of the ECM. The ECT sensor parameter should not change abruptly.

• If the ECT sensor parameter changes abruptly, repair the harness connector of the ECM.

3. Engine running, observe the ECT sensor parameter while moving the wiring harness between the sensor and ECM. The ECT sensor parameter should not change abruptly.

• If the ECT sensor parameter changes abruptly, repair the wiring harness.

Component Testing

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

Important: A thermometer can be used to the 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 table and verify that the resistance is within 5 percent of the specification.

• If the resistance vs. temperature is not within 5 percent, replace the ECT sensor.

Repair Instructions

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

* Engine Coolant Temperature Sensor Replacement
* Programming and Relearning for ECM setup, and programming Programming and Relearning