OBD-II code · Network
U063D Lost Communication With Hybrid/EV Electronics Coolant Pump A
The vehicle bus reports loss of communication with smart HV power-electronics coolant pump A. Inverter and DC/DC cooling cannot be commanded; derating may follow.
Is it safe to drive with U063D?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Hv Electronics Coolant Pump A, Vehicle Bus Wiring
Related codes
- U02BALost Communication With Hybrid/EV Electronics Coolant Pump B
- U02C1Lost Communication With Hybrid/EV Electronics Coolant Pump C
- U063ALost Communication With Hybrid/EV Electronics Coolant Temperature Sensor C
- U063BLost Communication With Coolant Bypass Valve Actuator A
- U063CLost Communication With Coolant Bypass Valve Actuator B
- U063ELost Communication With Exhaust Heat Exchanger Bypass Valve Actuator A
- U063FLost Communication With Engine Coolant Flow Control Valve Position Sensor
- U0640Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.