U063DLost Communication With Hybrid/EV Electronics Coolant Pump A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The first electric pump of the power electronics loop, A, circulates coolant through the inverter, DC/DC converter and similar parts. Pumps of this class, such as Bosch's PAD2, take their speed command via PWM or LIN and run their own diagnosis; with LIN the controller also expects regular status replies. U063D is set when pump A stops answering. No manufacturer documents U063D publicly. California's OBD II regulation covers the outputs of inverter cooling too, which makes a lit MIL likely on hybrids. If the pump is dead rather than just mute, P2C68 (stalled) or P0CEA (performance) tend to follow. Pumps B and C report the same fault as U02BA and U02C1. The electronics heat up and the system cuts power.
- What you may notice
- Hybrid system warning and MIL
- Reduced electric drive power or engine kept running on hybrids
- Inverter or electronics overtemperature messages
- Likely causes
- LikelyBlown fuse or open supply/ground to electronics coolant pump A
- PossibleLIN wire to the pump open, shorted or chafed
- PossiblePump electronics failed, often after running dry or overheating
- RareFault in the hybrid or thermal controller acting as bus master
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.