Engine Coolant Temperature Sensor 1 Out of Range
The coolant temperature sensor reading is 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 engine coolant temperature sensor is sending a reading that doesn't make sense; like it's showing too hot or too cold when it should be normal.
What the computer is actually seeing
The engine control module (ECM) expects the coolant temperature to be between 160°F and 220°F (71°C to 104°C) for normal operation. If it sees a value outside that range, it triggers this code.
What a healthy reading looks like
Coolant temperature should be between 160°F and 220°F (71°C to 104°C) under normal operating conditions.
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 engine coolant level—ensure it's not low. If it's low, refill and recheck the code after running vehicle.
- 22. Inspect the wiring and connectors to the coolant temperature sensor for damage or corrosion—repair any issues found.
- 33. Measure the voltage at the coolant temperature sensor connector with the key ON and engine OFF. You should see around 5V. If not, repair wiring as necessary.
- 44. Start the engine and monitor the coolant temperature using a scan tool. Compare this with a separate gauge if available. If temperatures are outside 160°F to 220°F, the sensor likely needs replacing.
- 55. If the sensor seems okay, check for ECM faults. Reflash or replace the ECM if needed.
Common causes
- Faulty coolant temperature sensor
- Wiring issues (shorts or opens)
- Low coolant level
- Malfunctioning ECM
- Corrosion at connector terminals
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but may cause engine running issues. Fix soon to avoid further damage.
Will this code come back after clearing?
It may return if the underlying issue isn't resolved.
Why do I see this code along with others like SPN 1159?
Multiple codes can indicate related issues, often stemming from the same sensor or system.
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