System: Powertrain (P-Code)
SAE Standard (Generic)
Family: EVAP Switching Valve Circuit
Code P2420: EVAP System Switching Valve Control Circuit High
Diagnostic & Technical Explanation
Code P2420 (EVAP System Switching Valve Control Circuit High) sets when the ECM detects an open circuit, a short, or out-of-range voltage while driving the EVAP system switching valve that redirects the monitor between the canister vent path and a natural-vacuum leak-check path. Causes are a failed valve solenoid coil, a corroded connector at the valve, or wiring chafed between the ECM and the valve near the charcoal canister.
First-listed procedure
Rank #1
Clean EVAP switching valve connector
Easy DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 2 procedure(s) are in the licensed dataset. Ordering context.
Full family: EVAP Switching Valve Circuit
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)