P0627 on Mercedes-Benz: How to Diagnose & Fix
Fuel Pump "A" Control Circuit/Open
1 Mercedes-Benz model · 1 documented issue · 1 critical · $900-$1,800 repair
P0627 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-Benz recalled 2021-2023 E-Class vehicles (NHTSA 23V-445, expanded by 23V-880) because the in-tank fuel pump impeller may not meet material specifications, can deform and rub the pump housing, and can shut the fuel pump down, causing loss of drive power; a warning message and rough running may appear first. 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
First check the VIN for open recalls 23V-445 / 23V-880; under the recall a Mercedes-Benz dealer replaces the fuel delivery module free of charge. 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.
Sources for this issue (2)
P0627 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 P0627 mean on a Mercedes-Benz?
P0627 stands for "Fuel Pump "A" Control Circuit/Open." This code means the engine computer detected an open (broken) circuit in the control wiring it uses to command the primary fuel pump, so it cannot reliably switch the pump on. The fuel pump delivers pressurized fuel to the engine, so a control-circuit problem can cause low fuel pressure, hard starting, stalling, no-start, or loss of power. Because it can leave the vehicle stranded, it should be diagnosed promptly. On Mercedes-Benz it is documented across 1 model: E-Class.
What are the most common causes of P0627?
The most common causes of P0627 are: Faulty fuel pump relay or fuel pump driver module, Open, damaged, or corroded wiring in the pump control circuit, Bad electrical connector at the pump, relay, or PCM, Blown fuse in the fuel pump circuit, Failed fuel pump (internal open), Poor ground for the fuel pump circuit, PCM/ECM control driver fault (rare). The specific cause varies by vehicle.
How much does it cost to fix P0627 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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.