What are the common causes of P04B0?

An open in the refueling vapor control valve coil. A broken wire in the refueling vapor valve circuit. Corrosion or a loose pin at the refueling valve connector. A blown fuse feeding the refueling vapor valve. A failed valve driver in the control module.

Check the refueling vapor valve fuse and feed for power. Inspect the refueling vapor valve connector for corrosion. Test the refueling vapor valve coil for continuity. Check the valve control wire for an open. Replace the refueling vapor control valve if the coil is open. Clear the code and retest.

P04B0

Refueling Vapor Control Valve Circuit/Open

System: Auxiliary emission controls (P code)
Lamp: Check Engine Light
Category: Powertrain - Auxiliary Emissions Controls

What it means

P04B0 means Refueling Vapor Control Valve Circuit/Open.

Where it lives

For P04B0, the circuit described runs through the valve. The description of P04B0 reports the valve as open.

Check these first

An open in the refueling vapor control valve coil
A broken wire in the refueling vapor valve circuit
Corrosion or a loose pin at the refueling valve connector
A blown fuse feeding the refueling vapor valve
A failed valve driver in the control module

What to do next

Check the refueling vapor valve fuse and feed for power
Inspect the refueling vapor valve connector for corrosion
Test the refueling vapor valve coil for continuity
Check the valve control wire for an open
Replace the refueling vapor control valve if the coil is open
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.