Hard starting or warnings
Check the 12-volt supply and stored faults before assuming the hybrid battery has failed. On hybrid versions, investigate the relevant high-voltage system separately.
S-Class care · Al Quoz 4, Dubai
Warning messages, a low suspension corner or hesitant gear changes can take the comfort out of your S400. Book servicing and fault diagnosis with MercGarage, then choose the repair and parts that suit your car.
Minor service estimates AED 950–1,250 including VAT. Hybrid, suspension and transmission work are quoted separately after the vehicle and fault are identified.

Tell us what changed
A useful appointment starts with your complaint, not a list of replacement parts. Tell us whether the problem appears at startup, after an overnight stop, in traffic or once the car warms up.
Check the 12-volt supply and stored faults before assuming the hybrid battery has failed. On hybrid versions, investigate the relevant high-voltage system separately.
Inspect air leaks, struts, valve control, compressor operation and height sensing on the fitted suspension. A slow leak can put extra demand on the compressor.
Distinguish gearbox behavior from engine misfires and worn mounts. Fluid condition, fault data, and a suitable road test guide the repair. See our Mercedes transmission repair options if the concern continues between services.
Find the leak or airflow problem before adding refrigerant or replacing a pump. Record whether cooling changes between stationary traffic and open-road driving.
Know the likely cost
These planning estimates include the listed parts, labor, fluids, and 5% VAT. They are not fixed offers. Your engine, fitted equipment, parts choice, and confirmed fault affect the final quote. Additional work requires your approval.
Approved engine oil, oil filter and routine checks. Confirm the oil quantity, filter specification and agreed inspections in your quote.
View minor-service inclusionsEngine oil and filter, engine-air and cabin filters, wider checks, and due spark-plug or brake-fluid work as itemized. Transmission service and fault repairs are separate.
Compare major-service work| Repair or service | Estimated AED | Included work and exclusions |
|---|---|---|
| Transmission oil and filter service | 950–1,800 | Correct fluid for the agreed drain-and-fill, filter, required pan seals, labor, level setting, and leak checks. Internal repairs and diagnosis are separate. |
| Accessible oil gasket or seal repair | 750–1,250 | One accessible leak source, compatible seal and normal fitting. Major dismantling, multiple leaks and internal engine work cost more. |
| Air suspension strut, one corner | 1,850–2,600 | One compatible reconditioned strut, fitting, ride-height checks, and applicable calibration. New genuine assemblies are quoted separately. Brand, condition, and coverage are stated before approval. |
| Hybrid coolant pump, where applicable | 1,300–1,800 | One compatible pump for the confirmed circuit, fitting, required coolant, bleeding, and function checks. Battery, inverter, and other cooling repairs are separate. |
| Initial diagnostic scan and report | 250 | Relevant fault-code scan, initial complaint review, and findings report. This is not a complete diagnosis of every fault. Extended testing, high-voltage investigation, dismantling, and repairs are separately quoted. |
Tell us the model year and the work you need. We can confirm the correct parts, inclusions, availability, and expected handover before your visit.
One badge, different systems
The chassis, engine and market specification matter more than a generic S400 package. The VIN helps identify the fitted powertrain, suspension and replacement components.
The earlier hybrid pairs a 3.5-liter V6 with electric assistance. Routine engine servicing remains essential, while high-voltage faults need a separate assessment from the 12-volt battery.
Confirm the hybrid equipment and exact battery application before ordering parts. Do not transfer battery location, cooling details or repair instructions from another generation.
Some S400 models use a conventional turbocharged engine. A turbo-related power-loss complaint belongs to that fitted system. An S400 d or older S400 CDI needs diesel-specific identification and maintenance.
Starting and hybrid concerns
The ordinary low-voltage battery supplies vehicle electronics. The high-voltage battery on an S400 Hybrid has a different job, price and repair procedure. A no-start complaint, disabled stop-start function or warning message alone does not prove which component has failed.
Ask for the findings behind a replacement recommendation. Checks may include low-voltage battery condition, charging behavior, relevant fault data, temperature control and communication between modules.

A supply, connection or cooling problem may be repairable without replacing the complete high-voltage pack. The repair decision depends on testing, not the age of the car alone.
Plan for AED 11,000–15,000 for a compatible reconditioned pack or AED 24,000–28,000 for a new genuine pack, installed with 5% VAT. Estimates include replacement labor, applicable setup, and final checks. Extended diagnosis, damaged supporting components, and any exchange deposit are separately identified. Compatibility, availability, and written coverage are confirmed before ordering.
Explore S400 hybrid battery replacementHigh-voltage work belongs with appropriately equipped technicians. Do not open the battery, disconnect orange cables or attempt an improvised repair.
Maintenance with a clear purpose
Use the ASSYST PLUS display, the vehicle maintenance requirements and your last invoices to decide what is due. Dubai driving conditions can inform the inspection, but they do not make one oil grade or one interval correct for every S400.
The foundation of routine care
Air and cabin filters, fault diagnosis, and repairs are separate. Allow approximately 1–2 workshop hours, subject to appointment availability.
Routine work plus the items now due
The quote lists the selected replacements; recently completed items can be removed. Allow approximately 3–5 workshop hours, subject to parts and appointment availability. AC recharge, hybrid batteries, suspension repairs, and gearbox work are separate.

The comfort you notice every day
Warm air at idle, weak airflow and different temperatures from adjacent vents need different checks. Refrigerant leaks, condenser airflow, the blower and temperature-control components should be assessed before choosing a repair.
Ride-height problems need air-system checks where fitted. Knocks and vibration can also involve control-arm bushings, tires or mounts. Brake judder needs disc, pad and related component inspection rather than a suspension assumption.
Intermittent seat, window, locking or COMAND faults can involve power supply, wiring or a specific module. Describe the affected function and when it stops working so the investigation stays focused.
A clear repair decision
Share the symptom, recent repairs and dashboard messages. STAR diagnostics and relevant physical checks help narrow the fault.
Review repair versus replacement where feasible, the named part and condition, labor, total price and expected timing.
The required checks depend on the repair, such as leak testing, a system rescan, calibration or a suitable road test.
“Booked online, got updates through WhatsApp, and the whole process was smooth.”Albert Tesla · Customer feedback published on the MercGarage homepage
Genuine Mercedes-Benz parts are available. If an alternative or reconditioned component is offered, ask for its brand, condition and compatibility. Request the applicable parts and labor warranty, duration and exclusions in writing.
This is general workshop feedback, not an S400-specific repair record or a promised completion time.
Plan your appointment
Prices, warning messages and booking details at a glance.
No. The S400 name appears on different powertrains and markets. W221 S400 HYBRID and W222 S400 Hybrid or S400 h require hybrid-specific checks. Other S400 versions use a conventional turbocharged engine. Send the year and VIN if you are unsure; the badge alone is not enough to order parts.
Minor servicing is estimated at AED 950–1,250 and major servicing at AED 2,450–3,250, including 5% VAT and the listed work. The engine, due items, and chosen parts affect the quote. Fault repairs and hybrid battery replacement are separate.
Not necessarily. The warning can involve the high-voltage battery, its temperature control, power electronics, connections or the low-voltage supply. The workshop needs the actual message and diagnostic findings before recommending a battery. Repeatedly clearing codes does not repair the cause.
Follow the exact dashboard instruction. Stop safely and arrange recovery if the car tells you to stop, loses propulsion, overheats, has impaired braking or sits low enough to rub a tire. If there is no immediate stop instruction or severe symptom, call with the message before deciding to drive to the workshop.
A service may help when the fluid is due and the transmission is otherwise healthy. It cannot guarantee a cure for worn clutches, a valve-body fault or an electrical problem. The quotation should separate maintenance from the repair needed for the shift complaint.
Allow approximately 1–2 workshop hours for minor service or 3–5 hours for major service. These are planning estimates, not guaranteed collection times. Hybrid battery orders and fault repairs need separate timing. Confirm the appointment and whether waiting is practical before traveling.
Pickup and drop-off can be arranged subject to availability, location and agreed charges. Request written warranty terms for the selected repair and parts. The coverage, duration and exclusions should be confirmed on the quote rather than assumed to apply equally to every job.
Start with your S400 model year, the service or symptom, and a photo of any dashboard message. Mileage and previous repair history help. The VIN can be requested when needed to confirm the engine, battery, suspension or replacement part.
Looking for S400 repair near you in Dubai? Contact MercGarage in Al Quoz 4 to discuss the fault or service due. Ask about pickup and drop-off arrangements, availability and charges when booking.
Start with the model year and your main concern. Vehicle details help us prepare an accurate quote.
Service images are illustrative and do not document completed customer repairs.