P0CBCDrive Motor A Coolant Temperature Sensor Circuit
- Generic OBD-II code · Powertrain
- Can trigger limp mode
- How the car detects it
- P0CBC is the general code for the sensor that measures coolant temperature in the cooling loop of drive motor A. Volvo and Polestar document it as P0CBC62 in the inverter module IEM of the Polestar 2 and the XC40/C40 Recharge (Technical Journals 37523 and 37521 from 2025): failure type 62 marks a signal comparison fault, and the vehicle displays a propulsion service message. In many of these cars the root cause was a defective check valve in a coolant hose, not the module. The phase transistor temperatures then swing widely while driving; at 80–100 °C the IEM sets a temperature code and freewheels, which stops a single-motor car and halves power on dual motors. Before replacing the IEM, plot those temperatures and renew the valve hose. CARB section (e)(15.2.3)(B)(ii) covers inverter cooling inputs.
- What you may notice
- Propulsion system service message
- Loss of drive power, car may stop on single-motor versions
- Half power only on dual-motor versions
- Likely causes
- LikelyFaulty one-way valve in the drive unit coolant hose (Volvo/Polestar TJ 37521/37523)
- PossibleLow coolant or trapped air in the drive motor loop
- RareSensor or wiring fault in the temperature circuit
- RareInternal fault of the inverter module
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.