Engine Coolant Temperature Sensor Circuit Out of Range
The engine's coolant temperature sensor is reading outside the expected range.
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 too high or too low, the engine control module (ECM) gets confused and may not adjust engine functions properly, affecting performance.
What the computer is actually seeing
The ECM expects the coolant temperature to be between 180°F and 220°F (82°C to 104°C). If it reads below 140°F (60°C) or above 240°F (115°C), it triggers this fault code.
What a healthy reading looks like
Normal coolant temperature readings should be between 180°F and 220°F (82°C - 104°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.
- 1Check coolant level; top off if low and recheck code.
- 2Inspect wiring and connector for damage or corrosion; repair as needed.
- 3Test coolant temperature sensor resistance at different temperatures; should match manufacturer specifications.
- 4If sensor is faulty, replace it and clear the code, then retest.
Common causes
- Faulty coolant temperature sensor
- Wiring issues or bad connections
- Low coolant level
- Faulty engine coolant temperature circuit in ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but may affect engine performance; fix soon.
Why does this code keep coming back?
Possible intermittent wiring issue or faulty replacement part.
Why does this code appear with others like SPN 1601?
These codes often trigger together due to a shared wiring harness or common sensor faults.
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