P0118-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH





For a complete wiring diagram Refer to Section 8W



Possible Causes
INTERMITTENT DTC
(K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K914) ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
(K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(K914) ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
ENGINE COOLANT TEMPERATURE SENSOR
ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. DTC IS ACTIVE

Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
Monitor the scan tool for at least two minutes.
Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time.
Start the engine.
Allow the engine to reach normal operating temperature.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE



Turn the ignition off.
Disconnect the Engine Coolant Temperature Sensor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the ASD Relay from the TIPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay Connector.
Turn the ignition on.
Measure the voltage of the (K2) Engine Coolant Temperature Sensor Signal circuit in the Engine Coolant Temperature Sensor harness connector.

Is there any voltage present?

Yes


No

3. (K914) ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE


NOTE: The jumper wire should still be in place.


Measure the voltage of the (K914) Engine Coolant Temperature Sensor Ground circuit in the Engine Coolant Temperature Sensor harness connector.

Is there any voltage present?

Yes


No

4. ENGINE COOLANT TEMPERATURE SENSOR



Turn the ignition off.
Remove the jumper wire and install the ASD Relay..
Connect the Engine Control Module (ECM) harness connector.
Connect a jumper wire between the (K914) Engine Coolant Temperature Sensor Ground circuit and the (K2) Engine Coolant Temperature Sensor Signal circuit in the Engine Coolant Temperature Sensor harness connector.
Turn the ignition on.
With the scan tool, Clear DTCs.
With the scan tool, select View DTCs.

NOTE: The scan tool should display an Engine Coolant Temperature Sensor low voltage or short to ground DTC with the jumper wire in place.



Does the scan tool display the DTC(s) as described above?

Yes


No

5. (K2) ENGINE COOLANT TEMPERATURE SENSOR SIGNAL OPEN OR HIGH RESISTANCE



Turn the ignition off.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance of the (K2) Engine Coolant Temperature Sensor Signal circuit between the Engine Coolant Temperature Sensor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

6. (K914) ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE



Measure the resistance of the (K914) Engine Coolant Temperature Sensor Ground circuit between the Engine Coolant Temperature Sensor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

7. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Coolant Temperature Sensor and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No