P1904 — Pressure Control Solenoid "C" Open Circuit

What Does P1904 Mean?

P1904 is a manufacturer-specific diagnostic trouble code: Pressure Control Solenoid "C" Open Circuit. This code applies to OTHER, FORD, LINCOLN, MERCURY vehicles. Unlike generic OBD-II codes, manufacturer-specific codes are defined by the vehicle maker and may only apply to certain makes and models.

Symptoms of P1904

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Pressure Control Solenoid "C" Open readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Pressure Control Solenoid "C" Open circuit (damaged, chafed, or corroded)
🔍 Faulty Pressure Control Solenoid "C" Open connector or terminal
🔍 Failed Pressure Control Solenoid "C" Open
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P1904 mean?

P1904 indicates: Pressure Control Solenoid "C" Open Circuit. The vehicle's computer has detected that the Pressure Control Solenoid "C" Open is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1904?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1904 for extended periods may cause additional problems.

How much does it cost to fix P1904?

Repair costs for P1904 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 Pressure Control Solenoid "C" Open wiring and connectors
🔧 Replace faulty Pressure Control Solenoid "C" Open

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.

P1904: Pressure Control Solenoid "C" Open Circuit