What it means
The control module detects that battery cooling fan 2 is not providing the expected cooling, or is stuck off. It sets the code when fan operation does not meet the monitored command or performance threshold.
How it works
Battery cooling fan 2 supplies airflow through the battery pack when the control module calls for cooling. The module monitors whether fan 2 responds and provides the expected cooling performance. P0A85 sets when fan 2 fails to operate as expected or remains off when needed.
Common causes
Most likely first.
- Faulty cooling fan motor
- Blocked fan or air duct
- Fan wiring or connector fault
- Faulty fan control module
Symptoms
- Hybrid system warning light
- Cooling fan does not run when needed
- Reduced power
How to diagnose it
- Review freeze-frame data and live fan commands to confirm fan 2 was requested when the fault was detected.
- Inspect fan 2's intake and the battery air duct for obstructions, accumulated debris, or collapsed sections.
- Check fan 2 wiring and connector for damage, looseness, corrosion, or signs of overheating.
- Use a scan tool's supported output test, if available, to command fan 2 and observe whether it runs and responds.
- If fan 2 does not respond despite sound wiring, test the motor and control module according to the manufacturer's procedure.
Common fixes
- Clear debris or other blockage from fan 2 and its air duct.
- Repair damaged wiring or clean and secure the fan 2 connector.
- Replace the fan 2 motor if it fails the manufacturer's test.
- Replace or repair the fan control module if it fails to command a verified fan and circuit.
Can I keep driving?
Avoid hard acceleration, heavy loads, and prolonged driving in hot weather if fan 2 is not operating or reduced power is present; battery cooling may be inadequate. Stop if the hybrid system limits power or displays a battery temperature warning, and arrange prompt diagnosis.
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.