P2C67: Hybrid/EV Electronics Coolant Pump A Overspeed

What it means

The hybrid electronics coolant pump A exceeds the calibrated maximum speed. Mechanical load lost or rotor position offset.

At a glance

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

How it works

Hybrid/EV electronics coolant pump A circulates coolant through the power-electronics cooling loop. The hybrid control module monitors its speed against the commanded duty and sets this code when pump A exceeds the calibrated maximum speed, which can occur if mechanical load is lost or rotor position is misread.

Common causes

Most likely first.

1. Mechanical coupling broken
2. Air pocket in coolant loop

Symptoms

• Check-engine light or hybrid-system warning
• Reduced hybrid power or performance
• Hybrid-system temperature warning

How to diagnose it

1. Read freeze-frame and live data for pump A command, reported speed, coolant temperature, and any related hybrid-system codes.
2. Inspect the pump A coolant loop for air-entry signs, low coolant, leaks, or a broken mechanical coupling.
3. Check pump A wiring and connector terminals for damage or poor contact that could disrupt speed or rotor-position feedback.
4. Follow the manufacturer's procedure to verify that reported pump speed changes appropriately with commanded duty.
5. If the loop and wiring are intact, test pump A coupling and rotor-position feedback as specified by the manufacturer.

Common fixes

• Correct low coolant or repair a leak that has allowed air into the pump A loop.
• Bleed the coolant loop using the manufacturer's procedure if air is confirmed.
• Repair a damaged pump connector or wiring fault.
• Repair a failed mechanical coupling or replace pump A if it cannot operate within its commanded speed range.

Can I keep driving?

Limit driving and avoid high loads because abnormal pump speed can mean the electronics are not being cooled as intended. Stop if a hybrid-system temperature warning appears or power is sharply reduced.