P04C1 — Fuel Fill Door Unlock Control Circuit Low

What Does P04C1 Mean?

P04C1 is a diagnostic trouble code indicating: Fuel Fill Door Unlock Control Circuit Low. This code relates to the emission controls system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P04C1

⚠️ Check Engine Light (MIL) illuminated
⚠️ Fuel Fill Door Unlock reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Failed emissions test

Common Causes

🔍 Open or broken wire in Fuel Fill Door Unlock circuit
🔍 Poor ground connection at Fuel Fill Door Unlock
🔍 Faulty Fuel Fill Door Unlock with no output signal
🔍 Disconnected or loose Fuel Fill Door Unlock connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P04C1 mean?

P04C1 indicates: Fuel Fill Door Unlock Control Circuit Low. The vehicle's computer has detected that the Fuel Fill Door Unlock is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P04C1?

Yes, P04C1 is generally safe to drive with in the short term. However, it should still be addressed to pass emissions testing and prevent potential secondary issues.

How much does it cost to fix P04C1?

Repair costs for P04C1 typically range from $20 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

🔧 Repair broken wire or restore ground in Fuel Fill Door Unlock circuit
🔧 Clean and secure Fuel Fill Door Unlock connector and ground points
🔧 Replace failed Fuel Fill Door Unlock

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.

P04C1: Fuel Fill Door Unlock Control Circuit Low