Engine Coolant Temperature Sensor 2 - Voltage Above Normal
The coolant temperature sensor 2 is reporting a voltage that is too high.
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What it means (plain English)
The second coolant temperature sensor is showing a voltage over its normal range, which usually happens when the sensor is faulty or wiring is shorted.
What the computer is actually seeing
The ECM sees voltage readings from the sensor that exceeds a typical maximum threshold of around 5 volts.
What a healthy reading looks like
Normal operating voltage for coolant temperature sensors typically ranges between 0.5 and 4.5 volts depending on the sensor type and temperature.
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 wiring and connectors to the coolant temperature sensor for damage or corrosion. Decision: If damaged, repair or replace wiring; if good, proceed.
- 22. Measure the voltage at the coolant temperature sensor connector with the engine at operating temperature. Expect around 2-3 volts. Decision: If over 4.5 volts, suspect a faulty sensor; if normal, check ECM for faults.
- 33. If the sensor voltage is high, replace the coolant temperature sensor and clear the code. Decision: If code returns, further investigate wiring or ECM issues.
- 44. Inspect the engine coolant level; ensure it’s within the proper range. Decision: If low, top off and retest; if okay, proceed.
Common causes
- Faulty coolant temperature sensor
- Shorted wiring or connectors
- Open circuit or poor ground connection
- Thermostat issues affecting coolant flow
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's advisable to fix this soon as it may impact engine performance and overheating risk.
Will this code come back after clearing it?
If the underlying issue isn't fixed, such as a failed sensor or wiring problem, yes, it will return.
Why does this code sometimes pair with SPN 1268?
SPN 1268 relates to the first coolant temperature sensor, so both can indicate coolant temp sensor issues.
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