Fault Family System: Powertrain (P-Codes) 5 SAE Codes

EVAP Refueling Vapor Valve Circuit

Diagnostic & Technical Explanation

Code P04B0 (Refueling Vapor Control Valve Circuit/Open) sets when the ECM detects an open, shorted, out-of-range, or mechanically stuck condition from the refueling vapor control valve used by the onboard refueling vapor recovery (ORVR) system to route fuel vapor to the canister only during refueling. Causes are a failed valve solenoid coil, a corroded connector, a valve stuck open/closed from fuel-vapor gum buildup, or damaged wiring to the valve.

These 5 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 5 times.

Codes in this family (5)

Code	Definition	Repair coverage
P04B0	Refueling Vapor Control Valve Circuit/Open	4 ranked fixes
P04B1	Refueling Vapor Control Valve Circuit Low	4 ranked fixes
P04B2	Refueling Vapor Control Valve Circuit High	4 ranked fixes
P04B3	Refueling Vapor Control Valve Stuck Performance/Stuck Open	4 ranked fixes
P04B4	Refueling Vapor Control Valve Stuck Closed	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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