Code 14
Code 14 is a diagnostic trouble code related to the coolant temperature sensor circuit on the Pontiac Fiero.
Code 14 indicates that the ECM is seeing a coolant temperature sensor signal that represents an unusually high coolant temperature.
Overview
The coolant temperature sensor is a thermistor. Its resistance changes with temperature. As coolant temperature rises, sensor resistance decreases.
Code 14 is set when the ECM detects a low-voltage signal from the coolant temperature sensor circuit. To the ECM, this indicates a very high coolant temperature reading.
This can be caused by an actual overheating condition, a faulty coolant temperature sensor, wiring problems, connector problems, or a short to ground in the sensor circuit.
Flash pattern
Code 14 is displayed as:
- One flash
- Pause
- Four flashes
This represents code 14.
Animated flash pattern:
Meaning
Code 14 usually indicates that the ECM sees the coolant temperature sensor circuit as too hot.
Possible causes include:
- Engine overheating
- Faulty coolant temperature sensor
- Coolant temperature sensor wiring problem
- Poor connector contact
- Short to ground in the sensor circuit
- ECM input problem
- Cooling system problem
Symptoms
Possible symptoms may include:
- Check engine light
- Hard starting
- Poor fuel mixture
- Poor idle
- Cooling fan behavior affected by incorrect temperature information
- Poor fuel economy
- Actual overheating, if the code is caused by a real cooling problem
Diagnosis
Basic diagnostic checks include:
- Confirm that Code 14 is present.
- Check whether the engine is actually overheating.
- Check coolant level when the engine is cool.
- Inspect the coolant temperature sensor connector.
- Inspect the sensor wiring for damage or shorts.
- Check for other stored trouble codes.
- Test the coolant temperature sensor resistance if equipment is available.
- Check the cooling system if the engine is actually running hot.
Related codes
Related coolant-temperature and cooling-system topics include:
- Code 15 - Coolant temperature sensor circuit, low temperature indication
- Overheating
- Cooling system
- Air in cooling system
Notes
Code 14 should not be treated as only an electrical code. First determine whether the engine is actually overheating.
If the engine is not overheating, the problem is more likely to be in the coolant temperature sensor, connector, wiring, or ECM input circuit.