Engine Coolant Temperature
Indicates a problem with the engine coolant temperature sensor.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine uses a sensor to monitor the temperature of the coolant; if it's too high or low, the system can’t operate efficiently, which can trigger warnings or limp mode.
What the computer is actually seeing
The engine control module expects the coolant temperature to fall within a typical range of 190°F to 220°F (88°C to 105°C). If it sees a reading below -40°F (-40°C) or above 257°F (125°C), it triggers the fault code.
What a healthy reading looks like
Engine coolant temperature typically ranges between 190°F and 220°F (88°C to 105°C).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check coolant level. If low, fill and retest.
- 22. Inspect the wiring and connectors to the coolant temperature sensor for damage or corrosion.
- 33. Measure resistance of the coolant temperature sensor. Expected value should change with temperature variations. (Check specific service manual for resistance vs. temperature chart.)
- 44. If the sensor is faulty, replace the coolant temperature sensor and retest.
- 55. If readings are still out of range, check the thermostat operation for proper opening and closing.
Common causes
- Faulty coolant temperature sensor
- Electrical issue (wiring or connectors)
- Cooling system leak
- Low coolant level
- Failed thermostat
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; driving is possible but monitor for overheating and performance issues.
What happens if I ignore this code?
Ignoring it may lead to overheating, engine damage, or reduced efficiency.
Does this code commonly pair with others?
Yes, it often appears with other temperature or sensor-related codes.
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