Engine Coolant Temperature Sensor 2
Indicates that the second engine coolant temperature sensor is out of 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 has two temperature sensors, and this code means the second one is reading either way too high or too low.
What the computer is actually seeing
The engine control module expects a signal from the coolant temperature sensor that ranges from 0.5V (about -40°C) to 4.5V (about 125°C). When it sees a reading below 0.2V or above 4.8V, it sets this code.
What a healthy reading looks like
Normal coolant temperature range is typically around 80-100°C (176-212°F), translating to a voltage of approximately 0.8-2.5V.
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 within the normal operating range. If low, refill and see if the code returns. Decision: If yes, check for leaks before proceeding.
- 22. Inspect the wiring and connector for the second coolant temperature sensor. Look for frays, corrosion, or loose connections. Decision: If damaged, repair or replace before testing further.
- 33. Use a scan tool to check live data from engine coolant temperature sensor 2. Note the voltage reading. Decision: If out of expected range (0.5V-4.5V), replace the sensor.
- 44. If sensor is within range, check for underlying issues such as engine overheating or issues with the first coolant temperature sensor affecting the second. Decision: Rectify any broader system problems if found.
Common causes
- Faulty engine coolant temperature sensor 2
- Wiring issues or corrosion in the sensor circuit
- Engine overheating or low coolant levels
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderately severe; you might experience engine performance issues. It's best to fix soon.
Will this code come back after clearing?
If the underlying issue isn't resolved, it likely will return.
Why is this sensor paired with SPN 100?
SPN 100 is the primary coolant temperature sensor; issues could stem from circuit problems affecting both.
Working a real vehicle right now?
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