P2CB3: Charge Air Cooler Coolant Pump B Stuck/Stalled

What it means

Charge air cooler coolant pump B reports a stuck/stalled condition. CAC coolant loop circulation 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 the charge air cooler loop to remove heat from compressed intake air. This code sets when the pump reports that its rotor is stuck or stalled, so the loop may have little or no circulation.

Common causes

Most likely first.

1. Pump impeller jammed
2. Motor seized

Symptoms

• Check-engine light
• Reduced engine power
• Possible charge-air temperature warning

How to diagnose it

1. Read freeze-frame data and live pump B status to confirm whether the stall occurs at startup or during operation.
2. With the engine cool and the vehicle safely switched off, inspect pump B and its connectors for impact damage, leaks or signs of overheating.
3. Check the CAC coolant hoses and reservoir for a blockage, kink or contamination that could obstruct the pump impeller.
4. Inspect pump B wiring, fuse and ground for an open or poor connection that could prevent the motor from turning.
5. If power and ground meet the manufacturer's specification, test pump B for a jammed impeller or seized motor.

Common fixes

• Reconnect or repair a loose or damaged pump B connector.
• Clear a blockage or correct a kinked CAC coolant hose.
• Replace a pump B fuse if it is blown, after checking for the cause.
• Replace pump B if its impeller is jammed or its motor is seized.

Can I keep driving?

Keep driving only as needed to reach a safe place, and avoid boost-heavy acceleration or towing because the CAC loop may not be circulating. Stop if a charge-air temperature warning appears or power falls substantially.