P0078 — Exhaust Valve Control Solenoid Circuit Bank 1

What Does P0078 Mean?

P0078 is a diagnostic trouble code indicating: Exhaust Valve Control Solenoid Circuit Bank 1. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P0078

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Exhaust Valve Control Solenoid readings
⚠️ Related system operating intermittently
⚠️ Poor fuel economy

Common Causes

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

Frequently Asked Questions

What does P0078 mean?

P0078 indicates: Exhaust Valve Control Solenoid Circuit Bank 1. The vehicle's computer has detected that the Exhaust Valve Control Solenoid is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P0078?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P0078 for extended periods may cause additional problems.

How much does it cost to fix P0078?

Repair costs for P0078 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 Exhaust Valve Control Solenoid wiring and connectors
🔧 Replace faulty Exhaust Valve Control Solenoid

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.

P0078: Exhaust Valve Control Solenoid Circuit Bank 1