P025A on Mercedes-Benz: How to Diagnose & Fix
Fuel Pump Module Control Circuit/Open
1 Mercedes-Benz model · 1 documented issue · 1 critical · $900-$1,800 repair
P025A on Mercedes-Benz by model: symptoms, diagnosis and fix
A number of late-model E-Class owners reported hard starting, long crank times, hesitation, and occasional stalling traced to low-pressure fuel supply faults, including in-tank fuel pump or delivery module issues. Mercedes service literature for related models and owner reports point to intermittent fuel pressure loss rather than a high-pressure pump problem in some cases. Symptoms can be sporadic at first and become a complete no-start as the pump weakens.
Common Symptoms
- Extended cranking
- Intermittent no-start
- Engine stalling
- Hesitation on acceleration
- Reduced power
- Whining noise from fuel tank area
How to Fix
Measure low-side fuel pressure during crank and under load, compare commanded versus actual values, and inspect pump current draw and fuel pump control operation. Repair usually involves replacing the in-tank fuel pump/delivery module and sealing ring, then clearing adaptations and verifying pressure stability on a road test. If contaminated fuel is suspected, inspect the tank and filter components as well.
Owner tips & cautions
- TipOwners recommend not ignoring occasional long-crank events; capturing fuel pressure data early can prevent getting stranded later.
P025A code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P025A mean on a Mercedes-Benz?
P025A stands for "Fuel Pump Module Control Circuit/Open." This code means the engine computer detected an open or abnormal voltage condition in the fuel pump (module 'A') control circuit, indicating a loss of electrical continuity. The computer commands the fuel pump control module to run the pump at the proper rate; if the control circuit is open or the expected feedback is missing, this code sets. It does not necessarily mean the pump itself is bad. It can cause hard starting, no-start, stalling, or reduced engine performance. On Mercedes-Benz it is documented across 1 model: E-Class.
What are the most common causes of P025A?
The most common causes of P025A are: Open or broken wiring in the fuel pump control circuit, Faulty fuel pump (driver) control module, Corroded or loose connector at the pump module, Faulty fuel pump assembly, Blown fuse or relay in the pump circuit, Poor ground connection, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P025A on a Mercedes-Benz?
Published repair estimates on Mercedes-Benz range from $900 to $1,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P025A on a different make?
View P025A across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.