Engine Coolant Temperature Sensor 2 Voltage Above Normal
Engine Coolant Temperature Sensor 2 is reporting high voltage.
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What it means (plain English)
The coolant temperature sensor sends signals to the computer about how hot the engine coolant is. If it reads too high, the computer thinks the coolant is overheating, which can affect engine performance.
What the computer is actually seeing
The engine control unit monitors the voltage output from the coolant temperature sensor. For normal operation, the expected voltage is between 0.5V and 4.5V, corresponding to temperatures from -40°C to 125°C (approximately -40°F to 257°F). If it sees values above 4.5V, it triggers SPN 1752.
What a healthy reading looks like
Voltage should be between 0.5V and 4.5V under normal operating conditions; above 4.5V triggers the 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. Check the engine coolant level—ensure it is at the correct level. If low, fill to the proper level and clear the code. If not low, proceed to step 2.
- 22. Inspect the wiring and connector for the coolant temperature sensor for damage or corrosion. Repair any found issues and clear the code. If there are no issues, proceed to step 3.
- 33. Measure the voltage at the coolant temperature sensor's connector while the engine is running. It should be 0.5V to 4.5V. If voltage is high (>4.5V), replace the sensor. If normal, fork to the PCM—proceed to step 4.
- 44. Check the ground circuit of the sensor. Measure voltage drop; it should be minimal (<0.2V). If the ground is bad, repair it. If good, suspect PCM fault and consider replacement.
Common causes
- Faulty coolant temperature sensor
- Open or short in the wiring harness
- Poor connector contact
- PCM (Powertrain Control Module) failure
- Grounding issues in the sensor circuit
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's best to avoid driving until fixed; overheating could cause engine damage.
Will this code come back after clearing?
If the underlying issue isn't fixed, it will likely return.
Why does this code pair with SPN 1751?
Both codes relate to different coolant temperature sensors; one might fail while the other is also affected.
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