P2420 — EVAP System Switching Valve Control Circuit High

What Does P2420 Mean?

P2420 is a diagnostic trouble code indicating: EVAP System Switching Valve Control Circuit High. This code relates to the powertrain system. It has been reported in NHTSA complaints across 1 different vehicle models.

Symptoms of P2420

⚠️ Check engine light illuminated

Common Causes

🔍 Faulty oxygen sensor
🔍 Sensor or control module malfunction

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"THE CHECK ENGINE LIGHT CAME ON WITH THE VSC AND SLIP LIGHTS ON THE DASH. HAD IT SCANNED AND THE CODES ARE P2195 AND P0138. I AM HAVING A HUGE PROBLEM WITH THIS, I FEEL THAT TOYOTA SHOULD COVER THIS PROBLEM OR ATLEAST MOST OF IT. IT'S $1700 TO FIX THIS PROBLEM THAT MANY AVALON OWNERS ARE OR HAVE HAD "
— Toyota Avalon owner, 03/17/2014

Source: NHTSA Complaints Database

Most Reported Vehicles for P2420

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	TOYOTA AVALON

Frequently Asked Questions

Can I drive with this code?

It depends on the severity. If the vehicle runs normally, short trips are usually OK. If you notice performance issues, drivability problems, or warning lights beyond the check engine light, get it checked soon.

Will this code clear itself?

Some codes clear automatically after the underlying issue is fixed and several drive cycles pass. But the root cause must be addressed first.

How do I find the exact cause?

A code alone doesn't pinpoint the failed part. You need a diagnostic scan ($50-150 at most shops) that reads freeze frame data and live sensor readings to identify the specific component.

What To Do Next

Possible Fixes

🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
🔧 Test the relevant sensor(s) with a multimeter before replacing
🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P2420: EVAP System Switching Valve Control Circuit High