Faulty engine coolant temperature (ECT) sensor; Damaged or disconnected wiring to the ECT sensor; Corroded or loose electrical connector at the ECT sensor; Open or shorted circuit in the ECT sensor signal or ground wire; Failed engine control module (ECM) or a software configuration issue; Low coolant level or air pockets causing the sensor to read incorrectly; Aftermarket or incorrect ECT sensor installed

DTC codes / P06xx · Computer and output circuits / P063F

P063FAuto Configuration Engine Coolant Temperature Input Not Present

P063F indicates that the engine control module (ECM) has not received a valid engine coolant temperature (ECT) signal during its automatic configuration or self-test routine. The ECM expects to see a plausible voltage from the ECT sensor when it runs its configuration check, and this code sets when that input is missing or out of range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaComputer and output circuits

Symptoms you may notice

Illuminated check engine light (malfunction indicator lamp) on the dashboard
Often no symptoms besides the warning light
Poor fuel economy or rich-running condition due to incorrect temperature data
Rough idle or stalling when the engine is cold
Inaccurate or inoperative temperature gauge on the instrument cluster
Cooling fan running constantly or not at all

Common causes, most likely first

Faulty engine coolant temperature (ECT) sensor
Damaged or disconnected wiring to the ECT sensor
Corroded or loose electrical connector at the ECT sensor
Open or shorted circuit in the ECT sensor signal or ground wire
Failed engine control module (ECM) or a software configuration issue
Low coolant level or air pockets causing the sensor to read incorrectly
Aftermarket or incorrect ECT sensor installed

How to diagnose and fix it

Check for any related diagnostic trouble codes (DTCs) and record freeze-frame data to understand when the fault occurred
Inspect the ECT sensor connector and wiring for damage, corrosion, or loose pins
Measure the resistance of the ECT sensor with a multimeter and compare to the manufacturer's temperature-resistance chart
Backprobe the ECT sensor signal circuit at the ECM to verify the voltage changes with temperature
Check for continuity and voltage drops on the sensor ground circuit
If the circuit and sensor test good, verify the ECM has the correct software calibration and perform a relearn or reprogram if required
Replace the ECT sensor if it fails resistance testing, then clear the code and verify the repair with a test drive

Don't overlook the coolant level and air pockets

A low coolant level or trapped air around the ECT sensor can cause a missing or erratic signal without any sensor or wiring fault, so always check the cooling system first.
The code can set intermittently due to a poor connection that only acts up with vibration or temperature changes, so wiggle-test the harness while watching live data.
Some vehicles require a configuration or relearn procedure after battery replacement or ECM replacement, and skipping it can trigger P063F even with good hardware.
A faulty thermostat that keeps the engine from reaching normal operating temperature can make the ECT signal appear implausible during the configuration check, mimicking a sensor failure.
Aftermarket sensors with incorrect resistance curves are a common cause of this code on vehicles that have had recent cooling system repairs.

Can I keep driving with P063F?

You can usually drive the vehicle with this code, but the engine may run less efficiently and the cooling fan may not operate correctly, so avoid heavy loads or long trips until it is diagnosed. If the temperature gauge is not working or the engine overheats, stop driving and seek professional help.

Tools that help

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