P2E45: Hybrid/EV Electronics Coolant Pump B Enable Circuit

What it means

Hybrid/EV electronics coolant pump B reports a enable circuit condition. Power electronics cooling on this branch is impaired.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Pump B moves coolant through one of the hybrid or EV power-electronics cooling branches. This code concerns the pump's enable circuit: the control module detects an enable-circuit condition that prevents it from reliably commanding or confirming pump operation.

Common causes

Most likely first.

1. Pump motor or driver fault
2. Air or coolant level issue

Symptoms

• Check-engine or hybrid-system warning light
• Reduced power or limited hybrid operation
• Possible power-electronics overheating warning

How to diagnose it

1. Save freeze-frame data and check hybrid-system live data for pump B enable status, command state, and related cooling faults.
2. Check the coolant level and inspect pump B's branch for leaks or air that could contribute to cooling warnings.
3. Inspect the pump B connector and enable-circuit wiring for loose connections, corrosion, chafing, or other visible damage.
4. Test the enable circuit for continuity, shorts, and connection quality against the manufacturer's specification.
5. If the circuit checks out, test pump B and its driver using the manufacturer's diagnostic procedure.

Common fixes

• Correct low coolant or bleed air from pump B's cooling branch as specified for the vehicle.
• Repair a loose, corroded, or damaged enable-circuit connection or wire.
• Replace pump B or its driver if testing confirms an internal fault.
• Clear the code and confirm pump B enables and cooling-system data responds normally.

Can I keep driving?

Drive only as needed and avoid high-load use because pump B may not run when required, risking power-electronics overheating or reduced hybrid operation. Stop if an overheating warning appears or the vehicle limits power.