Failing coolant temperature sensor with an internal intermittent short or low resistance; Chafed or damaged sensor wiring shorting to ground intermittently; Corroded, loose or contaminated connector terminals at the sensor; Water or coolant ingress into the sensor connector or harness; Fault in the signal reference or ground circuit shared with other sensors; Intake air temperature B sensor or its circuit fault, on engines that use it for this code; Internal fault in the engine control unit.

P1114

Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage IAT B Circuit Low Input.

Lincoln
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
1: AreaFuel and air metering
14: FaultThe specific fault in that area

What it means

On a Lincoln, P1114 means the engine control unit saw the signal from the engine coolant temperature (ECT) sensor circuit drop intermittently to a very low voltage. Some Ford-group listings also link it to the IAT B circuit, so the exact sensor monitored depends on the model and engine. A low voltage reading usually means a short to ground or a failing sensor, and because it is intermittent the fault comes and goes.

Symptoms

Check engine light on, possibly coming and going
Hard starting or extended cranking, especially when hot or cold
Rough idle or hesitation that appears intermittently
Poor fuel economy from the engine running rich
Cooling fans running at the wrong time or constantly
Temperature gauge reading erratically or showing the wrong value

Possible causes

Failing coolant temperature sensor with an internal intermittent short or low resistancelikely
Chafed or damaged sensor wiring shorting to ground intermittentlylikely
Corroded, loose or contaminated connector terminals at the sensorlikely
Water or coolant ingress into the sensor connector or harnesspossible
Fault in the signal reference or ground circuit shared with other sensorspossible
Intake air temperature B sensor or its circuit fault, on engines that use it for this codepossible
Internal fault in the engine control unitrare

How to diagnose

Read all stored and pending codes and note any other temperature or sensor circuit faults.
Review freeze frame data to see engine temperature, load and speed when the fault was set.
Check live data for the coolant temperature reading, looking for sudden jumps or implausible values compared with the actual engine temperature.
Visually inspect the sensor connector and harness for chafing, corrosion, moisture, bent pins and poor terminal tension.
With the engine running, gently wiggle the harness and connector while watching live data for sudden changes.
Measure the sensor resistance and compare it with the specification for your model and engine at a known temperature.
Check the reference voltage and ground at the sensor connector, and test the wiring for a short to ground.
If the sensor and wiring are good, check the IAT B sensor circuit where fitted, and consult model-specific information before suspecting the control unit.

How to fix

Replace the coolant temperature sensor if its resistance is out of specification or the reading is erratic.
Repair or replace damaged wiring, including any section shorting to ground.
Clean or replace corroded connector terminals and ensure the connector is fully seated and sealed.
Repair any ground or reference circuit fault found.
Replace the IAT B sensor if testing shows it is faulty on your engine.
Clear the codes after repair and road test to confirm the fault does not return.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but fix it soon. Wrong temperature data can cause poor running, rich mixture and incorrect fan operation, so keep an eye on the temperature gauge.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.