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P0078: Exhaust Valve Control Solenoid Circuit Bank 1

Severity
Medium
System
Fuel and Air Metering
Last reviewed: Last updated:

Methodology: We combine code standards with complaint and reliability patterns, then review for clear, vehicle-first diagnosis steps.

Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).

Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.

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

Common Causes

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. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

Related Codes

P0001 Fuel Volume Regulator A Control Circuit/Open P0002 Fuel Volume Regulator A Control Circuit Performance P0003 Fuel Volume Regulator A Control Circuit Low P0004 Fuel Volume Regulator A Control Circuit High P0005 Fuel Shutoff Valve A Control Circuit/Open P0006 Fuel Shutoff Valve A Control Circuit Low P0007 Fuel Shutoff Valve A Control Circuit High P0008 Engine Position System Performance Bank 1 P0009 Engine Position System Performance Bank 2 P000A A Camshaft Position Slow Response Bank 1