What it means
The vehicle bus reports loss of communication with smart A/C refrigerant distribution valve actuator D. Routing of refrigerant between cabin / battery / power-electronics chillers cannot be commanded.
How it works
A/C refrigerant distribution valve actuator D routes refrigerant among the vehicle's fitted thermal circuits, which can include the cabin, battery, and power electronics chillers. Its control module expects network messages from actuator D to command that routing. U062D sets when those messages are missing, so actuator D cannot be controlled through the bus.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module 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
How to diagnose it
- Scan all modules and save event data to determine which functions are affected and whether other distribution valve actuators also have communication faults.
- Check live data and command status for actuator D, comparing other valve actuators if the vehicle has them.
- Inspect actuator D's connector and accessible network wiring for damage, corrosion, loose pins, or moisture.
- Check the actuator's power and ground against the manufacturer's specification while following vehicle-specific high-voltage safety requirements.
- Test the communication circuit to actuator D for opens or shorts using the vehicle wiring diagram and manufacturer's procedure.
Common fixes
- Secure actuator D's connector or repair damaged wiring.
- Restore actuator D's power or ground.
- Repair an open or short in the communication bus serving actuator D.
- Replace actuator D after confirming its power, ground, and communication wiring are sound.
Can I keep driving?
The vehicle may lose cooling or thermal management for one or more systems and could limit power or disable affected functions. Follow vehicle warnings about thermal faults or reduced power, and stop if it indicates continued driving is unsafe.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.