Faulty engine coolant temperature sensor; Corroded or loose electrical connector at the sensor; Chafed or damaged wiring harness between the sensor and ECM; Coolant contamination or low coolant level causing sensor signal dropout; Poor ground connection for the sensor circuit; Failed thermostat keeping the engine from reaching normal temperature

DTC codes / GM codes / P1114

P1114 · GMEngine Coolant Temperature Sensor Intermittent

Q: What does code P1114 mean?

Engine Coolant Temperature Sensor Intermittent. P1114 on a GM vehicle indicates that the engine control module (ECM) has detected an intermittent signal from the engine coolant temperature (ECT) sensor. The ECM monitors the sensor's voltage and flags this code when the reading momentarily drops out or jumps erratically, rather than failing completely.

P1114 on a GM vehicle indicates that the engine control module (ECM) has detected an intermittent signal from the engine coolant temperature (ECT) sensor. The ECM monitors the sensor's voltage and flags this code when the reading momentarily drops out or jumps erratically, rather than failing completely.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Often no symptoms besides the warning light
Intermittent rough idle or stalling when the engine is cold
Poor fuel economy or rich-running condition
Cooling fan running constantly or not at all
Erratic temperature gauge readings
Hard starting or extended cranking in cold weather

Common causes, most likely first

Faulty engine coolant temperature sensor
Corroded or loose electrical connector at the sensor
Chafed or damaged wiring harness between the sensor and ECM
Coolant contamination or low coolant level causing sensor signal dropout
Poor ground connection for the sensor circuit
Failed thermostat keeping the engine from reaching normal temperature

How to diagnose and fix it

Inspect the ECT sensor connector for corrosion, tightness, and pushed-out pins
Check the wiring harness for chafing, heat damage, or loose grounds
Measure the sensor's resistance with a multimeter and compare to the GM temperature-resistance chart
Backprobe the sensor signal wire at the ECM and wiggle the harness to look for intermittent voltage changes
Verify coolant level and condition, and pressure-test the cooling system if low
Replace the ECT sensor if resistance is out of specification or the signal is erratic
Clear the code and perform a road test with a scan tool to confirm the repair

Why an intermittent ECT code misleads

A loose or corroded connector pin is more often the culprit than a failed sensor, so always wiggle-test the harness before condemning the sensor.
The ECM may substitute a default coolant temperature value when the signal drops out, which can mask driveability symptoms and make the code seem harmless.
Aftermarket sensors with incorrect resistance curves are a common cause of repeat P1114 codes on GM vehicles, so use a quality replacement.
A thermostat stuck open can keep the engine below the expected temperature range and trigger an intermittent ECT signal without any sensor fault.
The same intermittent signal can set companion codes for cooling fan control or fuel trim, so check for related codes before replacing parts.

Can I keep driving with P1114?

You can usually drive short distances with this code, but avoid long trips or heavy loads until it is repaired because an intermittent coolant temperature signal can cause poor fuel economy and cooling fan malfunctions. If the temperature gauge behaves erratically or the engine overheats, stop driving and diagnose immediately.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.