Engine Temperature Sensor Circuit
Indicates a fault in the engine temperature sensor circuit.
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What it means (plain English)
The engine temperature sensor reports back to the computer about how hot the engine is. If there's an issue, the computer won't get accurate temperature readings, which can lead to improper engine operation and efficiency.
What the computer is actually seeing
The engine control unit (ECU) uses the voltage from the temperature sensor. A normal sensor should output between 0.5V (cold) and 4.5V (hot). Faulty readings or open circuits can cause the code to trigger.
What a healthy reading looks like
Cold engine: 0.5V-1.0V; Normal operating temperature: 1.0V-2.5V; Hot engine: 2.5V-4.5V based on specific engine specs.
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 to the engine temperature sensor for visible damage or corrosion. Repair as necessary. If fine, proceed to step 2.
- 22. Test the voltage at the engine temperature sensor connector with the key on and engine off. You're looking for a consistent voltage between 0.5V and 4.5V. If it’s out of this range, replace the sensor and retest.
- 33. If the sensor and wiring are good, check the engine control module (ECM) for faults. Use a scan tool to check related settings and replace the ECM if necessary.
Common causes
- Wiring issues (frayed or broken wires)
- Faulty engine temperature sensor
- Bad connectors or corrosion
- ECU malfunction
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s moderate severity, so you can drive but plan to fix it soon to avoid performance issues.
Will this fault return after clearing it?
If the original issue isn't resolved, yes, it will likely come back.
Why does this code sometimes pair with SPN 110?
SPN 110 is related to engine coolant temperature, both are linked in monitoring the engine's thermal performance.
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