P2D55 code meaning
Hybrid/EV Battery Pack Coolant Temperature Sensor C Circuit High
Powertrain system Generic code P2Dxx codes Check engine light
What P2D55 means
P2D55 is the counterpart to P2D54: the signal of battery coolant temperature sensor C sits at or near the reference voltage. On an NTC circuit with pull-up that is what an open circuit produces, so the controller sees an impossibly cold coolant value. Typical findings are a connector not plugged back after battery work, a broken wire, a spread terminal, or a short to a supply line; an open sensor element is less common. No manufacturer documents P2D55 publicly. GM's sensor A equivalent P0C45 fails below -40 °C, at an ADC count above 3890 (2019) or 3823 (2011 Volt); either must persist for 1.75 of 2.5 s, Type B. CARB demands such out-of-range checks. Battery heating may not work properly in winter.
P2D55 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2D55
- Live data shows about -40 °C for sensor C
- Battery heating or cooling uses substitute values
- Warning light; reduced power in cold weather possible
Common causes of P2D55
- Most likelyOpen circuit: connector unplugged, broken wire or spread terminal
- PossibleSignal wire shorted to a supply voltage
- Less likelyOpen sensor element
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack coolant temp sensor cWiring harnessBms
What each part of P2D55 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 55 | The exact fault in that area. |
What to do next
- Note P2D55 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2D55
What does P2D55 mean?
P2D55 means "Hybrid/EV Battery Pack Coolant Temperature Sensor C Circuit High". P2D55 is the counterpart to P2D54: the signal of battery coolant temperature sensor C sits at or near the reference voltage. It is a generic code, so it means the same on every make.
Is it safe to drive with P2D55?
Drive gently and only to a workshop. With P2D55 the car can go into limp mode (reduced power) to protect itself.
Will P2D55 fail an emissions test?
Yes, it can. P2D55 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2D55 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2D55 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.