GM 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.
New to flash codes? The How to Read GM OBD-I Codes with a Paperclip walks through the test and what the numbers mean. The general OBD-I guide covers the rest.
What does GM code 14 mean?
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
- Check actual coolant level and engine temperature before condemning the sensor
- Read live coolant temp data through the ALDL port and compare to a thermometer
- Unplug the sensor and check whether the reading swings cold to confirm a shorted sensor
- Test sensor resistance against the factory temperature chart
- Repair wiring first since a shorted harness mimics a failed sensor
Sources and review
Review: qualified. Read the source limits below.
- GM and Chevrolet OBD1 Trouble Codes (ALDL Fault Code List)
live reference page (troublecodes.net)
Supports: code identity and GM meaning
Fetched directly. Single publisher, so the record is qualified, not verified. Causes and check order are curator-written from the circuit the code names.
Last updated 2026-09-19.
Report a correction for 14. Include your vehicle, the issue and a source if you have one.