What it means
The motor electronics coolant pump A control circuit reports a control circuit low condition. Power electronics cooling cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Motor electronics coolant pump A circulates coolant to remove heat from the inverter and associated hybrid power electronics. P0A06 sets when the pump A control circuit signal is below its expected electrical range, such as when the control wire is grounded or the pump has an internal short.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in pump motor
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid system or check-engine warning light on
- Possible reduced hybrid power
- Cooling fan may run more often
How to diagnose it
- Save freeze-frame data and check for pump A and inverter temperature-related codes to understand whether the low circuit signal coincided with a cooling problem.
- Inspect pump A's connector and control wiring for corrosion, damaged insulation, moisture, or a wire shorting to ground.
- With the hybrid system safely disabled according to manufacturer procedures, test the control circuit for a short to ground and check connector contact resistance.
- Test pump A's motor circuit for an internal short using the manufacturer's specification.
- If wiring and pump tests pass, follow the manufacturer's procedure to check the control output and confirm pump operation.
Common fixes
- Repair a pump A control wire shorted to ground.
- Clean or replace corroded connector terminals that create poor contact.
- Replace pump A if its motor is internally shorted or fails the specified test.
- Repair a faulty control connection if testing locates the low signal outside the pump.
Can I keep driving?
Do not continue a normal journey if this code is active, since pump A may not cool the hybrid power electronics and reduced-power operation may follow. Stop safely if a temperature warning appears or power is limited; continued driving can overheat and damage the inverter.
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.