What it means
The controller cannot drive the secondary fuel pump (B). Common on dual-tank trucks, GDI lift-pump systems, or alt-fuel installations — fault stops fuel delivery from this stage.
At a glance
- Usually lights the check-engine light
How it works
Fuel Pump B is the secondary pump stage identified by the vehicle's fuel-system design, and its controller switches or regulates power to that pump. P2632 sets when the controller detects an open control circuit, such as a broken connection, failed relay, or open pump motor winding, so the B pump may not operate.
Common causes
Most likely first.
- Open pump motor winding
- Failed pump relay
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
How to diagnose it
- Record freeze-frame data and check for fuel-pressure, pump-control, and starting-related codes to understand when Pump B failed to operate.
- Use the vehicle wiring diagram to locate Pump B, its relay, fuse, and connectors, then inspect for loose plugs, damaged wiring, corrosion, or a blown fuse.
- Command Pump B on with a scan tool if supported and listen or feel for relay and pump operation while checking the control state.
- Test for power and ground at the Pump B circuit and check relay operation against the vehicle wiring information.
- If supply and control wiring are intact, test the pump winding and fuel delivery using the manufacturer's procedure and specification.
Common fixes
- Reconnect or repair a loose or damaged Pump B connector or wire.
- Replace a failed Pump B relay or fuse after checking for the cause of failure.
- Repair an open ground or power feed to the Pump B circuit.
- Replace Pump B if its winding is open or the pump fails the specified delivery test.
Can I keep driving?
If the engine is hard to start, stalls, or loses power under load, avoid driving because fuel delivery can fail without warning. Tow the vehicle if it will not maintain steady power or repeatedly stalls.
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.