Engine Coolant Temperature Sensor 2 – Voltage Above Normal
Coolant temperature sensor 2 is reporting a voltage that's too high.
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What it means (plain English)
The engine has two coolant temperature sensors. Sensor 2 is sending a voltage higher than it should, which usually indicates a fault or wiring issue.
What the computer is actually seeing
The ECM expects the signal from coolant temperature sensor 2 to be typically between 0.5 volts (cold) and 4.5 volts (hot). If it sees a voltage over 4.5 volts, it triggers this code.
What a healthy reading looks like
Sensor output should be between 0.5V to 4.5V corresponding to the engine temperature (approximately 90°C to 105°C for normal operating conditions).
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 for corrosion or damage related to sensor 2. Connection must be tight and free of debris. Decision Point: If damaged, repair or replace. If good, move to step 2.
- 22. Measure voltage at the coolant temperature sensor 2 using a multimeter. Expect between 0.5-4.5 volts. Decision Point: If voltage is above normal (above 4.5V), replace the sensor. If normal, move to step 3.
- 33. Check for coolant leaks around sensor 2. If found, repair and clear the code. If no leak, move to step 4.
- 44. Inspect ECM for any related codes or issues that could affect sensor readings. If other codes present, diagnose those first.
Common causes
- Faulty coolant temperature sensor 2
- Wiring issues (short to voltage)
- Connector corrosion or damage
- Engine coolant leaks affecting sensor operation
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s not immediate unsafe, but the engine may not operate efficiently. Fix soon to prevent engine damage.
Will this code come back after clearing?
If the underlying issue is unresolved, the code will likely return.
Why does it pair with other sensor codes?
Multiple codes can indicate a systemic issue with the cooling system or wiring, often affecting multiple sensors.
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