What it means
The control module detects that inverter A cooling system performance is outside its expected range.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The inverter A cooling system circulates coolant to remove heat from the inverter power electronics. The control module monitors cooling-system performance and sets P0A93 when circulation or cooling for inverter A is inadequate, which can lead the hybrid system to reduce power to protect the electronics.
Common causes
Most likely first.
- Low coolant level
- Cooling pump or circulation problem
- Restricted coolant flow
Symptoms
- Check-engine or hybrid-system warning light
- Hybrid-system warning light
- Reduced hybrid power
How to diagnose it
- Read freeze-frame data and relevant coolant temperature or pump command readings to determine whether the fault appears as inverter A heats up.
- With the vehicle cool, check the inverter cooling reservoir level and look for visible leaks; do not open a hot cooling system.
- Inspect accessible hoses and the inverter A cooling circuit for kinks, damage, air intrusion, or signs of restricted flow.
- Check whether the inverter cooling pump runs and circulates coolant when commanded, following the manufacturer's procedure.
- If level, hoses, and pump operation appear normal, test for restricted flow or a cooling-system control fault using the manufacturer's diagnostic steps.
Common fixes
- Top up the correct coolant and repair any leak causing low level.
- Replace a failed inverter cooling pump or repair its electrical connection.
- Remove a confirmed restriction or correct trapped air using the manufacturer's procedure.
- Repair the inverter A cooling circuit control fault if testing identifies it.
Can I keep driving?
Avoid continued driving if the hybrid warning appears with reduced power, since overheating can damage inverter electronics and cause further power loss. Stop safely if the warning escalates or the vehicle limits propulsion.
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.