P2A83: Alternative Fuel Pump B Compression Stroke Valve Control Circuit/Open

What it means

The alternative fuel pump B compression stroke valve control circuit is open or has a fault.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

Alternative fuel pump B uses a compression-stroke valve to control fuel delivery during that part of the pump cycle. The control module monitors the valve circuit and sets P2A83 when the circuit for pump B is open or its electrical path is interrupted.

Common causes

Most likely first.

1. Open in valve control wire
2. Open valve coil
3. Pin pushed back out of connector body

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

1. Save the freeze-frame data and check live data for pump B’s valve command or circuit status to identify when the open circuit is detected.
2. With the ignition off, inspect pump B’s valve connector for a pushed-back pin, loose fit, corrosion, or damage.
3. Follow pump B’s control wiring and look for breaks, chafing, or a disconnected plug.
4. Check continuity through the control wire and connector using the vehicle wiring diagram.
5. Measure pump B’s valve coil and compare it with the manufacturer’s specification to determine whether the coil is open.

Common fixes

• Reseat and secure a pushed-back pump B connector pin.
• Clean corrosion and restore a sound connection at the valve connector.
• Repair a broken or disconnected control wire in pump B’s circuit.
• Replace pump B’s compression-stroke valve if its coil has no continuity or fails the specified test.

Can I keep driving?

Limit driving, especially under load, since an open pump B valve circuit can cause long cranking, loss of power, or stalling. If the engine stalls or will not start reliably, avoid driving it until repaired.