Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks the sensor that checks the temperature of the battery's cooling liquid is showing a number that's too high. It's like a thermometer saying it's really hot when it shouldn't be.
The P0C45 code indicates that the voltage signal from the battery pack coolant temperature sensor is higher than the expected range.
The Hybrid/EV Battery Pack Coolant Temperature Sensor A monitors the temperature of the coolant used to keep the battery pack at an optimal temperature. If the sensor's output voltage is too high, it suggests a possible sensor malfunction or a wiring issue that is causing the sensor to read inaccurately.
• Check engine light is on
• Possible overheating of the battery pack
• Reduced fuel efficiency
• Hybrid/EV system warning light
• Faulty battery pack coolant temperature sensor
• Wiring issues such as short to voltage or open circuit
• Faulty or corroded connectors
• Failure in the hybrid/EV control module
OBD-II: On-Board Diagnostics, a standardized system in vehicles for self-diagnosing and reporting
Coolant: A fluid used to prevent overheating by transferring heat away from the engine or battery
• Use an OBD-II scanner to confirm the code
• Inspect the battery pack coolant temperature sensor and wiring
• Check for any loose or corroded connectors
• Test the sensor's voltage output with a multimeter
• Replace the faulty battery pack coolant temperature sensor
• Repair or replace damaged wiring
• Clean or replace corroded connectors
• Reprogram or replace the hybrid/EV control module if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regularly check the battery cooling system
• Ensure proper maintenance of the vehicle's electrical system
• Inspect connectors and wiring for corrosion or damage
Sensor Issue
• Do not ignore the check engine light
• Have the vehicle inspected by a professional
• Avoid driving long distances until the issue is resolved
Check with the manufacturer for warranty coverage on hybrid/EV components.
This code has become more common with the increased use of hybrid and electric vehicles, as battery temperature management is crucial for performance and safety.
Moderate – It should be addressed soon to prevent potential damage to the battery pack.
Ignoring this code can lead to battery damage, which may be costly and pose safety risks.
• Vehicle must be in a safe location
• Ensure the engine is off and the vehicle is cool
The battery pack coolant temperature sensor is typically located near the battery pack, often integrated into the cooling system.
Q: Can I drive with a P0C45 code?
A: It's not recommended to drive for long periods with this code active, as it may lead to battery overheating.
Q: How do I reset the check engine light after fixing the issue?
A: You can use an OBD-II scanner to clear the code once repairs are complete.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when coolant-temperature and warm-up faults indicate a thermostat-related issue.
Coolant-temperature and warm-up faults often lead to thermostat testing and replacement.
Thermostats are vehicle-specific and should be matched by engine and housing style.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.