Redundant Sensor Failure - Engine Coolant Temperature (ECT)
The engine coolant temperature sensor has failed or is out of range due to redundancy checks.
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 computer monitors two ECT sensors for safety. If one fails, it can cause an error code, which means it can't trust the reading anymore.
What the computer is actually seeing
The ECU sees conflicting signals from the primary and redundant ECT sensors when they should be giving similar readings, causing it to recognize a fault.
What a healthy reading looks like
Normal ECT readings should range from 180°F to 220°F (82°C to 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.
- 11. Inspect the wiring and connectors for the ECT sensors for damage, corrosion, or loose connections. If found, repair as needed.
- 22. Check the engine coolant level; it should be at the recommended level. Top off if low and see if the code returns.
- 33. Use a multimeter or scan tool to test both ECT sensors. Compare the readings; they should be within 5°F of each other. If one is out of range, replace that sensor.
- 44. If both sensors are functioning correctly, check for ECU updates or faults. Reflash or replace the ECU if necessary.
Common causes
- Faulty engine coolant temperature sensor
- Wiring issues or poor connections in the ECT circuit
- Fluctuating coolant levels affecting sensor readings
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive my vehicle with this code?
It's drivable, but monitor for engine overheating or performance issues. Fix it soon.
Will this code come back after clearing?
It can if the underlying issue isn't fixed or if a faulty sensor is replaced with another bad one.
Why is there a redundancy check?
To provide a backup reading for critical systems like cooling, ensuring that if one sensor fails, the other can still provide vital data.
Working a real vehicle right now?
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