P2D03: Motor Electronics Coolant Pump A Supply Voltage Circuit

What it means

Motor electronics coolant pump A reports a supply voltage circuit condition. Power electronics cooling is impaired.

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 moves coolant through the power electronics cooling loop, and its supply circuit provides the electrical power it needs. The control module sets this code when it detects a fault in pump A's supply-voltage circuit, which can stop or impair cooling.

Common causes

Most likely first.

1. Supply fuse blown
2. Wiring or connector fault

Symptoms

• Check-engine or hybrid-system warning
• Power limited warning
• Reduced performance under load

How to diagnose it

1. Check freeze-frame data and live pump A status to see whether the fault coincides with a command to run or a loss of pump operation.
2. With the vehicle safely powered down, inspect pump A's supply wiring and connectors for damage, corrosion, looseness, or heat marks.
3. Check the designated pump A supply fuse and related connections for an open circuit or poor contact.
4. Check pump A grounds and wiring continuity using the manufacturer's procedure, isolating the circuit as directed.
5. Measure voltage at pump A under the commanded operating condition and compare it with the manufacturer's specification to locate a supply drop.
6. If the supply and wiring test correctly, follow the vehicle's procedure to determine whether the pump or its control electronics are reporting the fault.

Common fixes

• Replace a blown pump A supply fuse after checking for the cause of the overload.
• Clean and secure corroded or loose pump A supply and ground connections.
• Repair damaged or open wiring in pump A's supply circuit.
• Replace pump A if its supply circuit is correct but the pump still reports a supply fault.

Can I keep driving?

Because this fault can interrupt power electronics cooling, avoid heavy loads and continued driving if a power-limited or hybrid-system warning appears. Stop safely if power is reduced and have the electrical fault diagnosed promptly.