P26F8: Coolant Pump C Stuck/Stalled

What it means

The third coolant pump is commanded on but the rotor does not turn. Sediment, frozen coolant, or a foreign object jams the impeller.

At a glance

• Usually lights the check-engine light

How it works

Coolant Pump C moves coolant through its own cooling loop, and the control module compares the pump command with evidence that its rotor is turning. This code sets when the pump is commanded on but remains stalled, commonly because debris jams the impeller or the motor bearings have seized.

Common causes

Most likely first.

1. Impeller jammed by sediment or debris
2. Pump motor seized by bearing failure

Symptoms

• Engine or powertrain warning light may come on
• Temperature warning may appear if the affected cooling loop overheats
• Cooling performance may be reduced in the affected system

How to diagnose it

1. Record freeze-frame data and compare Pump C's commanded state with its reported speed or status in live data.
2. With the system cool, inspect the pump and its connectors for leaks, impact damage, loose wiring, or signs of contamination.
3. Check coolant level and condition in the affected loop, following the vehicle's safe filling procedure.
4. If accessible under the manufacturer's procedure, inspect the Pump C impeller or coolant passage for sediment or debris that could block rotation.
5. If the impeller is clear and the pump has power and command, test whether the rotor or motor is mechanically seized.

Common fixes

• Remove debris or sediment blocking the Pump C impeller or passage, where serviceable.
• Correct a low coolant level and address any cause of contamination.
• Replace Pump C if its bearing or rotor is seized.

Can I keep driving?

Do not continue driving if a temperature warning appears or the affected loop is overheating; a stalled pump can quickly worsen overheating. Stop safely and let the system cool before checking coolant.