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 not reach 15° C (60° F) in a predetermined time. Failure time varies from 2 to 20 minutes and is calculated from start up temperature, engine speed, and ambient temperature.
Diagnostic Test
1. PRE-DIAGNOSTIC 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(R), read PCM 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. CHECK FOR CURRENT DTC
NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB III(R) at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for a DTC.
With the ignition on.
With the DRB III(R), erase PCM DTCs.
NOTE: It maybe necessary to road test the vehicle for this DTC to set.
With the DRB III(R), read PCM DTCs.
Did this DTC set again?
Yes
- Go To 3
No
- Go To 11
3. MONITOR THE ECT SENSOR TEMPERATURE
With the ignition on.
With the DRB III(R), monitor the ENG COOLANT TEMP value.
Choose a conclusion that best matches the ENG COOLANT TEMP value.
If the value is greater than 169° C (336° F).
- Go To 4
If the value is less than -39° C (-38° F).
- Go To 7
If the temp value is within normal operating range.
- Go To 11
4. 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(R), monitor the ENG COOLANT TEMP value.
Is the value less than -38° C (-36° F)?
Yes
- Replace the Engine Coolant Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
No
- Go To 5
5. 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 above 100 kohms?
Yes
- Go To 6
No
- Repair the ECT Sensor Signal circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
6. ECT SENSOR SIGNAL CIRCUIT SHORT TO SENSOR GROUND CIRCUIT
With the ignition off.
Measure the resistance between the ECT Sensor Signal circuit and the Sensor Ground circuit at the ECT Sensor harness connector.
Is the resistance above 100 kohms?
Yes
- Replace and program the Powertrain Control Module.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
No
- Repair the ECT Sensor Signal circuit for a short to the Sensor Ground circuit.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
7. ENGINE COOLANT TEMPERATURE 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 at the ECT Sensor harness connector.
With the DRB III(R), monitor the ENG COOLANT TEMP value.
Is the value at or above 170° C (338° F)?
Yes
- Replace the Engine Coolant Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
No
- Go To 8
8. 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 Sensor harness connector.
Is the voltage below 1.0 volt?
Yes
- Go To 9
No
- Repair the ECT Sensor Signal circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
9. SENSOR GROUND CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the Sensor Ground circuit from the ECT Sensor harness connector to the PCM C3 harness connector.
Is the resistance less than 5.0 ohms?
Yes
- Go To 10
No
- Repair the ECT Sensor 5-volt Supply circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
10. ECT SENSOR SIGNAL CIRCUIT OPEN
With the ignition off.
Measure the resistance of the ECT Sensor Signal circuit from the ECT Sensor harness connector to 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. Powertrain Verification Test - Ver 2
No
- Repair the ECT Sensor Signal circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
11. 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 12
No
- Locate and repair any coolant leaks and add the necessary amount of coolant.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
12. ECT SENSOR RANGE
NOTE: This test works best on a cold engine.
Turn the ignition on.
With the DRB III(R), read the ENG COOLANT TEMP 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 ENG COOLANT TEMP value as well as the actual engine temperature with a thermometer. The ENG COOLANT TEMP value in the DRB III(R) should transition smoothly from start-up to operating temperature.
NOTE: As the engine warms to operating temperature, the actual coolant temperature and the ENG COOLANT TEMP value in the DRB III(R) should stay relatively close to each other.
Did the ENG COOLANT TEMP value in the DRB III(R) and the actual temperature stay relatively close to each other?
Yes
- Go To 13
No
- Replace the Engine Coolant Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
13. 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 14
No
- Replace the thermostat.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test - Ver 2
14. 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 DTCs.
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. 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.