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 found a problem with the sensor that checks the temperature of the liquid used to keep the hybrid or electric car's battery cool. It's saying the sensor is reading a temperature that's too high.
The P2D55 code is triggered when the powertrain control module (PCM) detects a high voltage signal from the battery pack coolant temperature sensor C, indicating a higher than expected temperature reading.
The Hybrid/EV Battery Pack Coolant Temperature Sensor C is responsible for monitoring the temperature of the coolant used to regulate the battery pack's temperature. A high circuit condition suggests that the sensor is sending a voltage signal that is above the normal operating range, which could be due to a faulty sensor, wiring issues, or actual high coolant temperatures.
• Check Engine Light is on
• Reduced fuel efficiency
• Overheating of the battery pack
• Possible limp mode activation
• Faulty coolant temperature sensor
• Wiring issues (e.g., short circuit)
• Actual high coolant temperature
• Faulty PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connections to the sensor
• Test the sensor's resistance and voltage output
• Check the actual coolant temperature
• Replace the faulty coolant temperature sensor
• Repair or replace damaged wiring
• Flush and replace the coolant if necessary
• Reprogram or replace the PCM if needed
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Toyota Prius
• Chevrolet Volt
• Nissan Leaf
• Regularly check and maintain coolant levels
• Inspect wiring and connectors periodically
• Ensure proper functioning of the cooling system
Sensor Issue
• Do not ignore the Check Engine Light
• Get the vehicle inspected by a professional
• Avoid driving the vehicle if overheating is suspected
Check with your vehicle manufacturer for warranty coverage on hybrid/EV components.
This code has been more prevalent with the increase in hybrid and electric vehicles, highlighting the importance of battery thermal management.
Moderate – While the vehicle may still operate, ignoring this issue can lead to battery damage and reduced vehicle performance.
Operating a vehicle with a malfunctioning cooling system can lead to overheating and potential safety hazards.
• Engine at operating temperature
• Vehicle stationary and in park
The coolant temperature sensor is typically located near the battery pack or within the cooling system's plumbing.
Q: Can I drive with a P2D55 code?
A: It's not recommended to drive with this code active as it may lead to battery overheating and damage.
Q: How serious is a P2D55 code?
A: It's moderately serious as it affects the cooling of the battery pack, which is crucial for vehicle performance and safety.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
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.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.
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.