P1200 — Fuel Pump Relay ECU Circuit Malfunction

What Does P1200 Mean?

P1200 is a manufacturer-specific diagnostic trouble code: Fuel Pump Relay ECU Circuit Malfunction. This code applies to LEXUS, BUICK, CADILLAC, CHEVY, CHRYSLER 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 P1200

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Fuel Pump Relay ECU readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Fuel Pump Relay ECU circuit (damaged, chafed, or corroded)
🔍 Faulty Fuel Pump Relay ECU connector or terminal
🔍 Failed Fuel Pump Relay ECU
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P1200 mean?

P1200 indicates: Fuel Pump Relay ECU Circuit Malfunction. The vehicle's computer has detected that the Fuel Pump Relay ECU is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1200?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1200 for extended periods may cause additional problems.

How much does it cost to fix P1200?

Repair costs for P1200 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 Fuel Pump Relay ECU wiring and connectors
🔧 Replace faulty Fuel Pump Relay ECU

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.

P1200: Fuel Pump Relay ECU Circuit Malfunction