P004B — Turbocharger/Supercharger Boost Control B Circuit Range/Performance

What Does P004B Mean?

P004B is a diagnostic trouble code indicating: Turbocharger/Supercharger Boost Control B Circuit Range/Performance. 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 P004B

⚠️ Check Engine Light (MIL) illuminated
⚠️ Turbocharger/Supercharger Boost Control B not operating within expected parameters
⚠️ Reduced efficiency or performance of related system
⚠️ Poor fuel economy

Common Causes

🔍 Turbocharger/Supercharger Boost Control B degraded or contaminated
🔍 Mechanical wear or binding in Turbocharger/Supercharger Boost Control B
🔍 Incorrect Turbocharger/Supercharger Boost Control B installed (wrong part number)
🔍 Related system mechanical issue affecting Turbocharger/Supercharger Boost Control B readings

Frequently Asked Questions

What does P004B mean?

P004B indicates: Turbocharger/Supercharger Boost Control B Circuit Range/Performance. The vehicle's computer has detected that the Turbocharger/Supercharger Boost Control B is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P004B?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P004B for extended periods may cause additional problems.

How much does it cost to fix P004B?

Repair costs for P004B typically range from $50 to $250, 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 clean Turbocharger/Supercharger Boost Control B
🔧 Replace degraded Turbocharger/Supercharger Boost Control B
🔧 Check for related mechanical issues affecting readings

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.

P004B: Turbocharger/Supercharger Boost Control B Circuit Range/Performance