P0116
DTC P0116 (LUW)
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 P0116
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Engine Coolant Temperature (ECT) Sensor Performance
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 V to the ECT 1 sensor signal circuit and a ground for the low reference circuit.
The purpose of the P0116 diagnostic is to analyze the performance of the ECT sensor by comparing the response and the range of the sensor signal to two distinct models under various operating conditions.
* The first model verifies that the sensor is not stuck in range.
* The second model verifies that the sensor is within an acceptable operating range of the calculated ECT. Both models use various parts of the information derived from the following inputs:
- Ambient air temperature
- ECT
- Engine OFF time
- Intake air temperature (IAT)
- Engine OFF time
Conditions for Running the DTC
* The ignition is ON, or the engine is running.
* DTCs P0111, P0112, P0113, P0117, P0118, P0722, P0723 or P2610 are not set.
* The ignition has been off for greater than 8 h before the engine is started.
* This DTC runs continuously within the enabling conditions.
Conditions for Setting the DTC
P0116 Engine Running, Sensor Signal Stuck Test
* The ECM detects that the ECT sensor signal has abruptly changed a minimum of 20°C (68°F) warmer than intake air temperature (IAT) at engine start.
* The measured ECT is greater than measured IAT at engine start, is not within range of the calibrated model.
P0116 Engine Running, Sensor Within Range Test
* The ECT at engine start is not within range of the calibrated model.
* The ECT is greater than measured IAT at engine start, is not within range of the calibrated model.
Action Taken When the DTC Sets
* DTC P0116 is a Type B DTC.
* The cooling fans will be commanded ON.
* The A/C compressor will be commanded OFF.
Conditions for Clearing the DTC
DTC P0116 is a Type B DTC.
Diagnostic Aids
* Inspect the ECT sensor terminals for corrosion and for engine coolant leaking through the sensor. Engine coolant that is leaking through the sensor will create a high resistance short to ground. This condition results in less voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a warmer ECT.
* An intake air temperature (IAT) sensor that is biased colder at various ambient temperatures due to greater resistance than is normal will increase the range between these 2 sensors. Measure and record the resistance of the IAT sensor at various ambient temperatures, then compare those measurements to the Temperature vs. Resistance table. Refer to Temperature Versus Resistance (ECT) Temperature Versus Resistance (ECT).
* Test the ECT sensor at various temperature levels in order to evaluate the possibility of a biased sensor. A sensor that is biased warmer can result in a driveability condition. Refer to Temperature Versus Resistance (ECT) Temperature Versus Resistance (ECT).
* A slight to moderate resistance in the IAT sensor signal circuit or low reference circuit will increase the range between these two sensors. This condition results in a greater voltage on the IAT sensor signal circuit, which is interpreted by the ECM as a colder IAT.
* If the condition is intermittent, allow the vehicle to sit for greater than 8 h with the ignition OFF, may help isolate the condition. Compare the scan tool and ECT Sensor temperature sensor values at ignition on. The Radiator Coolant Temperature Sensor and the ECT Sensor values should display within 3°C (5°F).
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (D61)
Description and Operation
Cooling System Description and Operation (1.4L LUV) Cooling System Description and OperationCooling System Description and Operation (1.8L LUW and LWE) Cooling System Description and Operation
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0112, P0113, P0117, or P0118 are not set.
• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition off, inspect the cooling system surge tank for the proper coolant level. Refer to Loss of Coolant Loss of Coolant and Cooling System Draining and Filling (Static Fill) Cooling System Draining and Filling (Static Fill)Cooling System Draining and Filling (GE-47716 Fill) Cooling System Draining and Filling (GE-47716 Fill).
3. If the ignition has been OFF for 8 h or greater, observe the scan tool parameters list below. The temperatures should be within 20°C (68°F).
* ECT Sensor
* IAT Sensor
4. Engine running, observe the ECT Sensor parameter. The reading should be between -40 to +140°C (-40 to +284°F) depending on the current ambient temperature and the vehicle operating conditions.
5. 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 B34A Engine Coolant Temperature Sensor 1.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 2 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
3. Ignition ON, verify the scan tool ECT Sensor 1 is at -40°C (-40°F).
• If warmer than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
Caution:
If the fuse in the jumper wire opens, the signal circuit may have a short to a voltage or a short to ground and the sensor might be damaged.
4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool ECT Sensor 1 is at 140°C (284°F).
• If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
5. If all circuits test normal, test or replace the B34A Engine Coolant Temperature Sensor 1.
Component Testing
Static Test
1. Ignition OFF, disconnect the harness connector at the B34A Engine Coolant Temperature Sensor 1.
Note:
A thermometer can be used to test the sensor off vehicle.
3. Test the B34A Engine Coolant Temperature Sensor 1 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance (ECT) Temperature Versus Resistance (ECT) table and verify that the resistance is within 5% of the specification.
• If not within the specified range, replace the B34A Engine Coolant Temperature Sensor 1.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Engine Coolant Temperature Sensor Replacement - Thermostat Side Engine Coolant Temperature Sensor Replacement - Thermostat Side
* Control Module References Control Module References for ECM replacement, programming, and setup