What it means
The vehicle bus reports loss of communication with smart HV battery pack coolant pump A. Active battery cooling cannot be commanded; charging/discharging power may be limited.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
Battery coolant pump A circulates coolant to manage the temperature of the hybrid or electric vehicle’s high-voltage battery. This code sets when the vehicle network loses communication with the pump, preventing the control system from reliably commanding active battery cooling and potentially limiting charging or driving power.
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
- Record freeze-frame data and scan the hybrid or EV modules for related communication and battery-temperature codes before clearing anything.
- Check live data for pump A communication status, battery temperature, and any available pump command or feedback to see whether the fault is current.
- With the vehicle powered down according to its service instructions, inspect pump A’s connector and bus wiring for damage, corrosion, or loose connections.
- Have the pump’s specified low-voltage power and ground checked; a supply fault can prevent the pump module from communicating.
- Test the communication wiring for an open or short using the vehicle wiring diagram and manufacturer procedures.
- If communication wiring and supply are correct, assess pump A’s module for internal failure before replacing it.
Common fixes
- Reconnect or repair a damaged pump A connector.
- Repair an open or short in pump A’s bus wiring.
- Restore the pump module’s power or ground.
- Replace battery coolant pump A if its wiring and supply are sound and the module has failed.
Can I keep driving?
Avoid long trips, hard acceleration, and high-power charging until the battery cooling fault is diagnosed; the vehicle may limit power, and battery temperature could rise without commanded cooling. Follow any high-voltage system warnings and arrange prompt service.
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.