(P0116) Engine Coolant Temperature Sensor Performance
(P0116) ENGINE COOLANT TEMPERATURE SENSOR PERFORMANCE
When Monitored and Set Condition
^ When Monitored: With the engine running and no fault in the throttle valve actuator.
^ Set Condition: LOW LIMIT: The ECT Sensor value is less than -39 °C (-38 °F) for more than 1 second. HIGH LIMIT: The ECT Sensor value is more than 170 °C (338 °F) for more than 1 second. CLOSED LOOP TEMPERATURE NOT REACHED: The engine coolant temperature does reach 15 °C (60 °F) in a predetermined time. Failure time varies from 2 to 20 Min and is calculated from start up temperature, engine speed, and ambient temperature.
POSSIBLE CAUSES
ENGINE COOLANT TEMPERATURE (ECT) SENSOR SIGNAL CIRCUIT OPEN
ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT OPEN
IMPROPER COOLANT LEVEL
ENGINE COOLANT THERMOSTAT
ENGINE COOLANT TEMPERATURE SENSOR
POWERTRAIN CONTROL MODULE
Diagnostic Test
1. PREDIAGNOSTIC CHECK OUT
Note: Low engine coolant level can be the cause of this DTC. If the fluid level is low locate and repair any leaks before diagnosing this DTC.
Note: Always perform diagnostics with a fully charged battery.
Note: Check connectors-Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Note: Check for applicable TSBs. Turn the ignition on.
With the DRB III, read DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
Go To 2
2. MONITOR THE ECT SENSOR TEMPERATURE
With the ignition on.
With the DRB III, monitor the ECT Sensor temperature value.
Choose a conclusion that best matches the ECT Temp value.
If the value is greater than 169 °C (336 °F).
Go To 3
If the value is less than -39 °C (-38 °F).
Go To 5
If the temp value is within normal operating range.
Go To 10
3. ECT SENSOR
Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Note: Check connectors-Clean/repair as necessary.
Turn the ignition on.
With the DRB III, monitor the ECT Sensor temperature.
Is the value less than -38 °C (-36 °F)?
Yes>> Replace the ECT Sensor.
Perform Powertrain Verification Test - Ver 2
No>> Go To 4
4. ECT SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the PCM C3 harness connector.
Note: Check connectors-Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of the ECT Sensor Signal circuit at the ECT harness connector.
Is the voltage above 1.0 volts?
Yes>> Repair the ECT Sensor Signal circuit for a short to voltage.
Perform Powertrain Verification Test - Ver 2
No>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2
5. ECT SENSOR
Turn the ignition off. Disconnect the ECT Sensor harness connector.
Note: Check connectors-Clean/repair as necessary.
Turn the ignition on.
Connect a jumper wire between the ECT Sensor Signal circuit and the ECT Sensor Ground circuit.
With the DRB III, monitor the ECT Sensor temperature.
Is the value at or above 170 °C (338 °F)?
Yes>> Replace the ECT Sensor.
Perform Powertrain Verification Test - Ver 2
No>> Go To 6
6. OPEN ECT SENSOR 5-VOLT SUPPLY CIRCUIT
With the ignition on.
Measure the voltage of the ECT Sensor 5-Volt Supply circuit at the ECT Sensor harness connector.
Is the voltage between 4.5 - 5.2 volts?
Yes>> Go To 8
No>> Go To 7
7. OPEN ECT SENSOR 5-VOLT SUPPLY CIRCUIT
Turn the ignition off. Disconnect PCM C3 harness connector.
Note: Check connectors-Clean/repair as necessary. Measure the resistance of the ECT 5-Volt Supply circuit from the ECT harness connector and the PCM C3 harness connector.
Is the resistance less than 5.0 ohms?
Yes>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2
No>> Repair the ECT Sensor 5-Volt Supply circuit for an open.
Perform Powertrain Verification Test - Ver 2
8. ECT SENSOR SIGNAL CIRCUIT SHORT TO GROUND
Turn the ignition off. Disconnect PCM C3 harness connector.
Note: Check connectors-Clean/repair as necessary.
Measure the resistance between ground and ECT Sensor Signal circuit.
Is the resistance below 100 ohms?
Yes>> Repair the ECT Sensor Signal circuit for a short to ground.
Perform Powertrain Verification Test - Ver 2
No>> Go To 9
9. OPEN ECT SENSOR SIGNAL CIRCUIT
With the ignition off.
Measure the resistance of the ECT Sensor Signal circuit from the ECT
harness connector and the PCM C3 harness connector.
Is the resistance less than 5.0 ohms?
Yes>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2
No>> Repair the ECT Sensor Signal circuit for an open.
Perform Powertrain Verification Test - Ver 2
10. CHECKING THE COOLANT LEVEL AND CONDITION
WARNING: NEVER OPEN THE COOLING SYSTEM WHEN THE ENGINE IS HOT. THE SYSTEM IS UNDER PRESSURE. EXTREME BURNS OR SCALDING MAY RESULT. ALLOW THE ENGINE TO COOL BEFORE OPENING THE COOLING SYSTEM.
Turn the ignition off.
Check the coolant level and condition.
Is the coolant level and condition OK?
Yes>> Go to 11
No>> Locate and repair any coolant leaks and add the necessary amount of coolant.
Perform Powertrain Verification Test - Ver 2
11. ECT SENSOR RANGE
Note: This test works best on a cold engine.
Turn the ignition on.
With the DRB III, read the ECT Sensor value. If the vehicle was allowed to sit overnight, the value should be reasonably close to the ambient temperature.
Note: If engine coolant temperature is above 85 °C (185 °F), allow the engine to cool until at least 65 °C (150 °F).
Start the engine.
During engine warm-up monitor the ECT Sensor value as well as the actual engine temperature with a thermometer. The ECT temperature value in the DRB III should transition smoothly from start-up to operating temperature.
Note: As the engine warms to operating temperature, the actual coolant temperature and the ECT value in the DRB III should stay relatively close to each other.
Did the ECT value in the DRB III and the actual temperature stay relatively close to each other?
Yes>> Go to12
No>> Replace the ECT Sensor.
Perform Powertrain Verification Test - Ver 2
12. CHECKING COOLANT THERMOSTAT OPERATION
Turn the ignition off.
Remove the thermostat.
Using the appropriate service information, perform thermostat diagnosis.
Did the thermostat open at the proper temperature and to the proper stroke?
Yes>> Go to 13
No>> Replace the thermostat.
Perform Powertrain Verification Test - Ver 2
13. INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
Note: Check connectors-Clean/repair as necessary. Poor pin to terminal connections can set DTC's.
Note: Check for any Technical Service Bulletins that may apply.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
Were there any problems found?
Yes>> Repair as necessary.
Perform Powertrain Verification Test - Ver 2
No>> The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.