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Mercedes-Benz E550 common problems: what to check before you buy

Credov's researched list of the 3 faults the Mercedes-Benz E550 is known for (2005–2008), 3 of them serious or costly. Each one says what to look for when you check the car, so you can spot it before you buy. Not every car has these faults: they are the ones worth checking on this model.

Known problems on the Mercedes-Benz E550

SBC brake unit fault

Safety risk

2005–2006 · Brakes

What to look for: With the ignition on, check for any brake warning message, and feel for a hard or long brake pedal.

Why it matters: When the SBC unit faults the car drops to a back-up hydraulic mode with a much harder pedal and longer stopping distances, and Mercedes dropped SBC altogether at the 2006 facelift after persistent problems.

Sources: 1 2 3

SAM module water ingress

Costly if missed

2005–2008 · Electrical

What to look for: Look under the scuttle panel for leaves and standing water, and lift the boot floor for damp or tide marks.

Why it matters: Water in a SAM module causes a scatter of dash warnings, lights or wipers acting up and flat batteries, and a water-damaged module usually needs replacing and re-coding rather than drying out.

Sources: 1 2

7G-Tronic conductor plate

Costly if missed

2009–2016 · Gearbox

What to look for: From cold, check for smooth shifts through every gear, no thump into Drive and no flare between gears.

Why it matters: A failing conductor plate can put the car into limp mode without warning, and while some confused shifting is fixed by a software update or reset, a hard failure needs the valve body or plate replaced.

Sources: 1 2 3

Got a question about a Mercedes-Benz E550? Ask Credov: a noise, a warning light, a part or how to fix it.

Also check on every car

On top of the faults above, every Credov inspection covers the basics: fuel smell, leaks or filler rust, engine oil leaks, power steering fluid leak, drive belt cracks or squeal, rust underneath: chassis and mounts, engine mounts, engine oil level and colour, coolant level, colour and leaks, head gasket failure signs, cold start: rattle, knock or smoke, rough or hunting idle, engine running hot on gauge, gearbox or diff oil leak, swapped gearbox without lvv and more.

Other Mercedes-Benz models

Researched by Credov from manufacturer recalls and service bulletins, owner reports and workshop sources. Repair prices are typical ranges, not quotes. See also fault codes and repair costs.