What it means
Charge air cooler coolant pump B reports a control circuit/open 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
Charge air cooler coolant pump B circulates coolant through the charge air cooler loop, helping remove heat from compressed intake air. This code sets when the control circuit for pump B is open, so the pump may not run and charge-air cooling can be impaired.
Common causes
Most likely first.
- Open in pump control wire
- Open pump motor
- Pin pushed back out of connector body
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Charge-air temperature warning, if equipped
How to diagnose it
- Record freeze-frame data and check for related charge-air temperature or pump codes to understand when pump B stopped responding.
- With the engine off, inspect pump B's connector for a pushed-back pin, loose fit, corrosion, or water intrusion.
- Follow the pump B control harness and look for an open, chafed, pinched, or disconnected wire.
- Use the scan tool's supported output control, if available, to command pump B and listen or feel for operation while observing circuit response.
- Test pump B's motor and control circuit continuity against the manufacturer's specification to locate an open in the motor, wiring, or connector.
Common fixes
- Seat the backed-out or loose pump B connector terminal correctly.
- Repair an open or damaged pump B control wire.
- Replace pump B if its motor winding is open or it fails the manufacturer's specification.
- Repair a confirmed control-side connection fault.
Can I keep driving?
Drive gently and avoid sustained acceleration or towing because the charge air may run hotter and engine power may be reduced. Stop if a charge-air temperature warning appears or the engine loses significant power.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.