14 Engine Coolant Temp Sensor Error High Temp Indicated

How to read it

Code 14 reads as 1 flash, pause, 4 flashes on the check-engine light. Jump terminals A and B on the ALDL connector with the key off, then turn the key on with the engine off and count the check-engine flashes.

What does GM code 14 mean?

14 — Engine Coolant Temp Sensor Error High Temp Indicated. This code sets when your vehicle computer detects engine coolant temp sensor error high temp indicated.

Common causes of 14

• Shorted coolant temp sensor or signal wire to ground
• Corroded sensor connector pulling voltage low
• Actual engine overheat from low coolant or a stuck thermostat
• Damaged sensor wiring routed against hot exhaust parts

How to fix 14

1. Check actual coolant level and engine temperature before condemning the sensor
2. Read live coolant temp data through the ALDL port and compare to a thermometer
3. Unplug the sensor and check whether the reading swings cold to confirm a shorted sensor
4. Test sensor resistance against the factory temperature chart
5. Repair wiring first since a shorted harness mimics a failed sensor