Engine Coolant Temperature
This code indicates an issue with the engine coolant temperature sensor or circuit.
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 (ECT) sensor measures how hot the engine coolant is, which helps the computer make decisions about fuel delivery and ignition timing.
What the computer is actually seeing
The computer monitors the voltage signal from the ECT sensor, which should range from about 0.5V (cold) to 4.5V (hot). A reading outside of typical ranges can trigger this code.
What a healthy reading looks like
Expected voltage from the sensor should be approximately 0.5V to 4.5V depending on coolant temperature: 0.5V at -40°F, 2.0V at 150°F, and 4.5V at 250°F.
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 the wiring and connector to the ECT sensor for damage or corrosion. Repair as necessary.
- 2Using a multimeter, measure the voltage at the ECT sensor while the engine is at operating temperature. It should be around 2.0V. If not, continue to step 3.
- 3Disconnect the ECT sensor connector and measure resistance across the terminals. Resistance values should correspond to the expected temperature range. If values are inconsistent, replace the ECT sensor.
Common causes
- Faulty ECT sensor
- Open or shorted wire in the sensor circuit
- Corroded connector or bad ground
- Coolant leaks affecting temperature readings
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; the vehicle may run poorly, so it's best to fix it soon.
Will this issue return after repair?
If properly repaired, it shouldn't return unless there are underlying issues like wiring problems.
Why is this paired with SPN 62?
SPN 62 commonly indicates related temperature sensor issues, which can happen due to similar causes.
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