Temperature Sensor 2 Circuit High
Indicates a problem with the second temperature sensor's circuit signaling high values.
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What it means (plain English)
The second temperature sensor is reporting an unusually high temperature reading, meaning the sensor might be faulty or there's an issue in the wiring.
What the computer is actually seeing
The engine control module (ECM) sees voltage levels from the temperature sensor that exceed the expected threshold, usually above 4.5 volts, indicating a possible open circuit or sensor failure.
What a healthy reading looks like
Normal operating voltage from the temperature sensor should be between 0.5 to 4.5 volts; anything above 4.5 volts triggers this code.
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 connector for the second temperature sensor for any visible damage or corrosion. Repair or replace as necessary. Decision: If wiring/connector is damaged = Repair/replace. If okay, go to Step 2.
- 22. Measure the voltage at the temperature sensor connector with a multimeter. You should see between 0.5 and 4.5 volts with the engine running. Decision: If voltage is within spec = Go to Step 3. If out of spec, replace the sensor.
- 33. Check the resistance of the temperature sensor (if accessible) when at ambient temperature; it should typically read between 2kΩ and 3kΩ. Decision: If resistance is within the range = ECM may be faulty. If out of range, replace the sensor.
Common causes
- Faulty temperature sensor
- Corroded or damaged wiring
- Loose connector at the sensor
- ECM malfunction
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's moderately safe to drive but fix it soon; high temperature readings might cause overheating issues.
Will this code come back after repair?
If the underlying issue is truly fixed (bad sensor or wiring), the code should not return.
Why does this code sometimes appear with SPN 4107?
SPN 4107 and SPN 4108 are related to temperature sensors, so issues often overlap, indicating problems with multiple sensors.
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