P0117
DTC P0117 or P0118 (Without L96)
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
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 signal circuit and supplies a ground to the low reference circuit.
Conditions for Running the DTC
P0117
* The engine is running for greater than 10 s.
OR
* The ignition is ON when the intake air temperature (IAT) is less than 50°C (122°F).
* This DTC runs continuously when the above conditions are met.
P0118
* The engine is running for greater than 10 s.
OR
* The ignition is ON when the IAT is greater than 0°C (32°F).
* This DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
P0117
The ECM detects that the ECT is warmer than 150°C (302°F) for greater than 5 s.
P0118
The ECM detects that the ECT 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.
Conditions for Clearing the MIL/DTC
DTCs P0117 and P0118 are Type B DTCs.
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
Warning
Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.
1. Turn OFF the ignition.
2. Inspect the cooling system surge tank for the proper engine coolant level. Refer to Cooling System Leak Testing (Component Tests and General Diagnostics) and Cooling System Draining and Filling (Vac-N-Fill) (Service and Repair)Cooling System Draining and Filling (Static Fill) (Service and Repair).
3. Turn ON the ignition, with the engine OFF.
4. Use the scan tool to verify the proper operation of the engine cooling system fans.
5. Turn OFF the ignition.
6. Verify the proper heat range, and the operation of the thermostat. Refer to Thermostat Diagnosis (Thermostat Diagnosis).
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B34 ECT sensor.
2. Ignition OFF for 90 s, test for less than 5 ohm between the low reference circuit terminal A 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 ECM.
3. Ignition ON, verify the scan tool ECT parameter is colder than -39°C (-38°F).
• If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Install a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT parameter is greater than 149°C (300°F).
• If less 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 ECM.
5. If all circuits test normal, test or replace the B34 ECT sensor.
Component Testing
Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature vs Resistance table. Refer to Temperature Versus Resistance (Temperature Versus Resistance).
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 ECM replacement, setup, and programming