EVAP System Switching Valve Control Circuit High
The P2420 code means the vehicle's onboard diagnostic system has detected: EVAP System Switching Valve Control Circuit High. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $75 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light illuminated
- Failed emissions inspection
- No driving performance impact
- EVAP system monitor not completing
- Possible fuel odor
Probable Causes (Ranked by Likelihood)
- Open circuit in EVAP switching valve wiring Very High
- Disconnected EVAP valve connector High
- Failed EVAP valve with open coil winding Moderate
- Broken wire in harness to EVAP valve Moderate
Frequently Asked Questions
Can I drive with code P2420?
Yes, completely safe to drive. Only the EVAP system is affected.
What causes P2420?
Usually a disconnected connector or broken wire. Check the connector first for a quick fix. Rodent damage to wiring is also common.
Is P2420 expensive to fix?
Typically $75 to $350. A disconnected connector costs nothing to fix. Solenoid or wiring replacement is moderately priced.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check if the EVAP switching valve connector is plugged in
-
Measure solenoid coil resistance (infinite means open)
-
Inspect wiring from ECM to the valve for breaks
-
Check for damage from rodent chewing on wires
-
Verify voltage at the valve connector with key on
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2012-2020 Subaru Crosstrek
- 2013-2021 Subaru Impreza
- 2014-2022 Toyota Camry
- 2011-2019 Honda CR-V
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