P2B6A: Coolant Pump D Stuck/Stalled

What it means

Coolant pump D reports a stuck/stalled condition. Coolant circulation through the affected loop 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

Coolant pump D moves coolant through its assigned loop, while the control module checks whether the pump responds and turns as expected. P2B6A sets when the pump is commanded but is detected as stuck or stalled, often because debris blocks the impeller or the motor has seized.

Common causes

Most likely first.

1. Pump impeller jammed by debris
2. Motor seized

Symptoms

• Check-engine light
• Engine or a coolant-cooled component may run hotter than usual
• Cabin heat or cooling performance may be reduced

How to diagnose it

1. Record freeze-frame data and review pump D command, feedback, and related coolant temperatures to confirm the stall occurs when the pump is requested.
2. With the system cool, inspect the pump D connector and harness for damage that could interrupt operation.
3. Check the coolant level and look for signs of contamination or debris that could reach the pump.
4. If access permits, inspect pump D and its coolant passages for a blocked impeller or obstruction, following the manufacturer’s procedure.
5. Check pump D power and ground while commanded, then assess whether the motor turns freely and responds as specified.

Common fixes

• Correct low coolant or contamination after finding and addressing its cause.
• Remove debris blocking pump D or its coolant passage, if accessible and serviceable.
• Repair a damaged pump connector or power and ground wiring.
• Replace pump D if its motor is seized or the impeller cannot turn.

Can I keep driving?

Avoid driving if temperature rises, cabin heat suddenly fades, or a coolant warning appears; stop and let the system cool. A stalled pump D can allow its coolant loop to overheat, potentially damaging the engine or the component it serves.