P063F

What it means

P063F is a generic powertrain code meaning the engine control module expected an engine coolant temperature input to be present as part of its automatic configuration, but could not find it. The ECM checks which sensors and inputs should exist for the fitted engine or variant, and sets the code when the coolant temperature signal is missing or not recognised. Exact behaviour and how the input is supplied (direct sensor or over the network) depends on the make and model.

Symptoms

• Engine management warning light on
• Hard starting or extended cranking, especially when cold
• Cooling fans running constantly or at the wrong time
• Poor fuel economy or rough running
• Temperature gauge reading incorrectly or not at all
• Reduced power if the ECM enters a limp mode

Possible causes

• Open circuit, damaged wiring or poor connector contact in the coolant temperature sensor circuitlikely
• Faulty coolant temperature sensor giving no usable signallikely
• Sensor unplugged or connector corroded or loose after recent workpossible
• Wrong or outdated ECM configuration after a replacement control unit or software updatepossible
• Network communication fault if the coolant temperature value is received from another modulepossible
• Internal ECM fault in the sensor input circuitrare

How to diagnose

1. Read all stored and pending codes and record the freeze frame data, noting engine temperature and conditions when the code set
2. Check for other coolant temperature, sensor supply or communication codes that point to the same circuit
3. Inspect the coolant temperature sensor, its connector and the wiring for damage, corrosion, chafing or water ingress
4. View live coolant temperature data and compare it with a known engine temperature when cold and while warming up
5. Check the sensor resistance against the manufacturer specification and test the wiring for continuity, short circuits and the reference voltage supply
6. Confirm whether the model takes this input directly from a sensor or over the network, and check the relevant wiring or module accordingly
7. Check whether the ECM has been replaced or reprogrammed recently and verify its configuration matches the vehicle
8. Clear the code after repair and road test to confirm it does not return

How to fix

• Repair or replace damaged wiring and clean or refit the connector terminals
• Replace the coolant temperature sensor if it fails resistance or signal checks
• Reconnect or secure any unplugged or loose connector
• Reload the correct configuration or latest approved calibration where an outdated or wrong setup is the cause
• Repair the network fault or replace the module supplying the temperature signal if the diagnosis points there
• Replace or repair the ECM only after wiring, sensor and configuration have been ruled out

Can I keep driving?

Nearby codes

• P063EGenericAuto Configuration Throttle Input Not Present Bank 1
• P0640GenericIntake Air Heater Control Circuit