P340C — Deactivation/Exhaust Valve Control Circuit Bank 1

What Does P340C Mean?

P340C is a diagnostic trouble code indicating: Deactivation/Exhaust Valve Control Circuit Bank 1. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P340C

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Deactivation/Exhaust Valve readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Deactivation/Exhaust Valve circuit (damaged, chafed, or corroded)
🔍 Faulty Deactivation/Exhaust Valve connector or terminal
🔍 Failed Deactivation/Exhaust Valve
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P340C mean?

P340C indicates: Deactivation/Exhaust Valve Control Circuit Bank 1. The vehicle's computer has detected that the Deactivation/Exhaust Valve is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P340C?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P340C for extended periods may cause additional problems.

How much does it cost to fix P340C?

Repair costs for P340C typically range from $80 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect and repair Deactivation/Exhaust Valve wiring and connectors
🔧 Replace faulty Deactivation/Exhaust Valve

1
Find your vehicle above
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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.

P340C: Deactivation/Exhaust Valve Control Circuit Bank 1