P0118
DTC P0117 or P0118 (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 P0117
- Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage
DTC P0118
- Engine Coolant Temperature (ECT) Sensor Circuit High Voltage
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 sensor signal circuit and a ground for the low reference circuit.
The following table illustrates the difference between temperature, resistance, and voltage:
Conditions for Running the DTC
P0117
* The ignition is ON or the engine is running.
* This DTC runs continuously within the enabling conditions.
P0118
* The engine is running for greater than 15 s.
* The intake air temperature (IAT) is warmer than -7°C (19.4°F).
* This DTC runs continuously within the enabling conditions.
Conditions for Setting the DTC
P0117
The ECM detects that the ECT sensor signal is warmer than 150°C (302°F) for greater than 5 s.
P0118
The ECM detects that the ECT sensor signal is colder than -60°C (-76°F) for greater than 5 s.
Action Taken When the DTC Sets
* DTCs P0117, and P0118 are Type B DTCs.
* The cooling fans will be commanded ON.
* The A/C compressor will be commanded OFF.
Conditions for Clearing the DTC
DTCs P0117, and P0118 are Type B DTCs.
Diagnostic Aids
* The engine coolant temperature gauge will display full cold when an ECT DTC sets.
* After starting the engine, the engine coolant temperature sensor temperature should rise steadily, then stabilize after the thermostat opens.
* Test the engine coolant temperature sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor can result in a driveability condition.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Cooling System Description and Operation 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. Engine running, observe the scan tool ECT Sensor parameter. The reading should be between -39 to +138°C (-38 to +280°F) depending on the current Ambient Air Temperature, the engine run time, and the vehicle operating conditions.
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 B34A Engine Coolant Temperature Sensor.
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 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 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.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B34A Engine Coolant Temperature Sensor.
2. Test the B34A Engine Coolant Temperature Sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance (ECT) Temperature Versus Resistance (ECT)Temperature Versus Resistance (IAT) Temperature Versus Resistance (IAT) 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.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Engine Coolant Temperature Sensor Replacement (Water Outlet) Engine Coolant Temperature Sensor Replacement (Water Outlet)Engine Coolant Temperature Sensor Replacement (Radiator) Engine Coolant Temperature Sensor Replacement (Radiator)Engine Coolant Temperature Sensor Replacement (Thermostat) Engine Coolant Temperature Sensor Replacement (Thermostat)
* Control Module References Control Module References for ECM replacement, programming and setup.