Engine Coolant Temperature Sensor Fault
The engine coolant temperature sensor is reporting an out-of-range value.
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 coolant temperature sensor measures how hot the engine coolant is. If it's showing too low or too high of a temperature when the engine is at normal operating temperature, it can trigger this fault code.
What the computer is actually seeing
The ECM expects a coolant temperature signal typically between 180°F and 220°F (approximately 82°C to 104°C). If the signal is below 140°F (60°C) or exceeds 250°F (121°C), the code sets.
What a healthy reading looks like
Coolant temperature should be around 195°F (91°C) during normal operation.
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 the coolant level; ensure it's within the proper range. Decision: Is coolant level low? If yes, refill and see if code returns. If no, proceed to step 2.
- 22. Inspect the wiring and connectors at the coolant temperature sensor for damage or corrosion. Decision: Is wiring intact? If no, repair or replace the wiring. If yes, proceed to step 3.
- 33. Check the resistance of the coolant temperature sensor at various temperatures using a multimeter. Expected resistance: at 195°F (91°C), around 200-300 ohms. Decision: Is resistance within range? If no, replace the sensor. If yes, proceed to step 4.
- 44. If all prior checks are good, there may be a concern with the ECM. Use manufacturer scan tool for further diagnostics.
Common causes
- Faulty coolant temperature sensor
- Wiring or connector issues
- Low coolant level
- Faulty ECM processing
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can drive it but should address it soon to avoid overheating issues.
Will this code come back?
If the underlying issue isn't fixed, yes, it'll likely return.
Why does it sometimes pair with SPN 1213?
SPN 1213 indicates a similar problem with the sensor where it could indicate overheating or malfunctioning if paired.
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